Not all class E starports conform to the description of a frontier installation. Indeed, no world with a decent population would be a frontier in that sense.
The so-called class E starport on Zila is described in a way that would earn it a C classification from me any time. It has a big staff and multiple buildings, it is visited regularily by 5000T freighters to fetch cargoes and more 5000T freighters passing through on their way back and forth between Aramis and the Vargr frontier.
The description in The Traveller Adventure does not explain just what it is that makes Zila's starport class E. Evidently it does not choose to sell refined fuel and/or provide minor repairs to visiting tramps. It's certainly not because low traffic makes having a fuel purifier plant and a small repair shop economically infeasible. All J1 ships and many J2 and J3 ships going to and from the Towers Cluster and the interior of the Marches will pass through Zila and want to buy refined fuel and effect the occasional minor repair.
Respect the roll is my motto. What should otherwise be a thriving trade center has put out the 'galaxy go away' sign, so why not respect that in the setting?
Nothing more canon then the starport descriptions. Don't understand the 'gotta support this POV through canon' arguments, then ignore the most basic bedrock rules. Let's be honest here, we are ALL IMTU.
Anyway, you can have a world with shipyards, boatyards, repair shops, and all the facilities needed to move millions of tons, but if for some strange reason (religious?) it chooses not to provide repairs to all visiting starships in a timely fashion, it doesn't get any better than an E classification.
Just reread the E classification. It's quite specific. NO facilities whatsoever. So this is your IMTU definition, which is fine, I certainly go off the reservation for things that make sense to me, but I don't think that just because it makes sense to you makes it 'more canon'.
You may say that it's very strange that an Imperial starport with a decent amount of trade would choose not to provide refined fuel and repairs, and I couldn't agree with you more. But that's a result of a world generation system that doesn't have any correlation whatsoever between population size (or even population level

) and starport class. Personally I'm sorely puzzled that TPTB have not fixed that glaring problem decades ago, but as they haven't, the obvious solution is to do as GDW did in the case of Zila: Ignore the E classification and assume the starport can handle whatever trade it gets.
Yes, it's overdue to link the two- if you want a specific range of A starports, then the pop should get a starport mod roll. I'm using RTT Worldgen and couldn't care less about the OTU so I simply don't have these issues, in that system the starport is rolled off of both population and industry levels.
Obvious to you. It's equally obvious to me that the place is the equivalent of an Alaskan bush slab of runway and nothing else, place likely sees nothing bigger then a 400-ton ship on a subsector subsidized mail run every week.
But I'm not comparing pop A worlds with class B or C starports with pop 1 worlds with D and E starports. I'm comparing them to pop 1 worlds with B or C starports.
Hmmm, ok, point taken given that you are dealing with 1000s of OTU weirdness-es and the situation comes up more often than the rare oddball description will cover.
10 people producing 11,000 dT of trade goods per week? No. Just no. Not even with automated factories (which is not something the Traveller rules really embrace). Just the security force needed to protect those auto-factories
1 from raiders would run into the hundreds.
1 Asuming for purposes of argument that such auto-factories were economically feasible in the Third Imperium (Which would open up a huge can of worms and wreck the built-in economics completely).
Well again, I am not afraid of discombobulating the Imperium with bots because I'm not there. But I am dealing with the economics and politics that are much closer to our era and sociology which does care very much about employment, and I'm not afraid of the occasional highly automated facility.
Partially because using RTT Worldgen avoids a lot of that, but also the principle of the owner is totally responsible for bot actions makes minimal supervision robots a real liability, as they can work reliably for decades then be presented with a situation that causes them to act badly and tear things up much more quickly without stopping then an equivalent human crew.
There aren't robotic ships that see making populated world space within a light minute IMTU because of interstellar law that prohibits automated things being able to crash into stations or worlds- but they are out there in belts and dwarf mining planets.
But since the Imperium is in most people's interpretation more a loose trade and defense confederation then anything else, it would make sense that there is not a universal 'employment mandate', enough cautionary disasters that few organizations or governments will 'go bot', but some will and it doesn't screw everything up.
Besides, if you cut off most people from employment, who will buy your stuff, and what will you do to avoid making them feckless rebellious trouble?
As for pop to tonnage ratio, who is to say that is all planetary production/consumption? A starship yard alone could consume a lot of that, and you can have transshipment points, where the tonnage is being reshuffled/redirected to break up a larger cargo into smaller lots for local J-1/2 delivery runs.
You can certainly have worlds produce trade goods an order of magnitude above or below the average. Which would make your 10 people produce like 100 and your 10 billion produce like 1 billion. And we'd still be talking productions proportionate to the population size rather than the population level.
I highly disagree, productivity, market desire and usage will be as individual as each planet.
Why not explore each planet's economic weirdness rather then trying to stamp a standard economic model on it? Use the strange as a jumping off point, not something to be stamped out or ignored?
I just don't see the pop ratio thing being some universal rule, even in 20th century times with places like India and China did not getting that much shipping compared to industrial powers or places like Germany or Russia pre-Cold War getting much less shipping per capita due to a continental approach (equivalent to an in-system economy without generating interstellar tonnage).
Postwar Gerrmany is an export machine, far more tonnage going out then before. Same 'UWP', but entirely different economic and business model, which changes the shipping picture dramatically.
I say forego the dead hand of ratio and let each place be it's own thing. More interesting story and different conflicts to arise.
Trade is an economic activity.
Yes, but I am focusing on generating hulls and a traffic pattern picture, not the internal economic mechanisms of each planet/system. If I want to I can drill down to interesting places and probably find years of play activity per system, but that would take a LOT of effort to work out per every system in a subsector. This gives me a quick gen, and I can color inbetween the lines later for content.
I'm not playing Traveller, I'm developing Traveller setting details and rules of thumb for developing setting details. I prefer those details to be at least half-way plausible.
Great. So am I.
But inevitably people will have different results.
Please take a spin through my revised formula, and what is your answer to my crowded skies critique? Are you really ready to have a setting that has that many ships of that big a tonnage to support the OP's conception of planetary tonnage requirements?
Keep in mind he's quoting tonnages for a train wreck of a planetary economy- for a TL15 pop A Starport A, the tonnages would be MUCH higher for his and I am presuming your model, that's a LOT of ships on the lanes to the 100D limit to support all that.
Big part of why I went with the smaller multiples in my formula, I want a specific effect and gameplay which involves 'classic' levels of traffic.
If you go with the OP's tonnage, and the likely multiples for better off planets, are you prepared for that many ships in the lanes as a logical result for your gameplay?