If by "former BTRL staff" you mean Omniscapper, I haven't seen him around for a while. If you mean Diaspora team, I don't think they would object to use of a project they abandoned (BTRL stuff is used left and right anyway, because it's surprisingly high quality, yet generic and not performance intensive).
Also, making a mod for BTRL effectively mean a full TC. There just isn't enough stuff in there for anything but basic mods.
If anything, I'd prefer a "TC creation pack", which would include interface templates (and a ready to use example), some basic HUD, necessary UI and ship sounds, fonts and other things needed to run FS (without ships or weapons). If a mod doesn't use any retail models or references retail tables, you should be able to run it on such pack. Of course, if you're making a mod of that size, custom HUD, UI and sounds are something you'd want to be original anyway (lack of custom HUD is one of relatively few drawbacks of WoD, which could, with a few additions, be turned into a standalone).