Save Vargr Space!
Please, for the love of the Ancients, do not get it in your heads to populate any more sectors coreward of the Vargr Extents with anything other than Vargr. It matters not how friendly other sophonts are or how stealthy they are passing coreward through the Extents or Enclaves. It doesn't matter what era or timeframe, especially the Vargr Pillaging era. There are enough Corsair Bases and Naval Bases across the Extents and Enclaves to turn anything less than a Tigress-class to dust.
Please do not devaluate the Vargr Extents with any more non-Vargr shenanigans in those coreward sectors. The Akumgeda, Gvegh, Nakagun, Logaksu, Urzaeng, Suedzuk and Roth Thokken will own your "colonial exodus", eat your "from the galactic core", or Long Night escapees for breakfast, lunch and dinner.
If you must develop unclaimed sectors anywhere near Vargr Space, might I suggest rimward-trailing Rfigh and Tar'G'kell'p Sectors? What's out there, you might ask? Yileans, Suedzuk Vargr, Roth Thokken, some far-ranging Irilitok, and K'kree. There is just enough to maintain an unexplored frontier by developing the rimward-trailing subsectors.
There are reasons why the sectors coreward of the Vargr Extents are uncolonized. Please do not dilute and de-fang the Vargr by developing there. Exceptions to this are revising faulty sectors, especially the ones with duplicate worlds. Dhuerorrg, Ngathksirz and Fa Dzaets are in dire need of rectification.