On one hand I'm opposed to this since it would screw up immersion - Terran Empire ships docking at ESD? Doesn't work.
On the other hand, we already have Ferengi, Cardassian and Jem'Hadar ships playable, so the above problem is essentially moot. I guess it could work if we have a good reason for Terran ships being in Federation Starfleet.
Sorry to get off-topic, but if Material 5 is the Terran skin, then why not let us use it for ship costumes in the Foundry?