Trilon had a number of reasons for going the independent route. First, as an Outward corporation, they see the tight web of regulations governing Core corporations to be a leash, holding them back. Relocating to Kie-Yuma was simply the start of what they see as the next wave of human expansion, driven by profit-minded ideologies of expansion. They also see trade with the Pentapods as becoming vitally important, and have been trying to negotiate with several Pentapod nations to set up a Trilon enclave in Pentapod space, with a reciprocal Pentapod enclave on Kie-Yuma.
Trilon has it eye on the Bayern corridor, and possibly what lays beyond it. After all, they are all about expansion, including expansion of the Human potential.