TL;DR- I’ll suggest it to the admins but it’s extremely doubtful.
We did, for about an hour, run an FTB server alongside the regular server. Only Dan, Devore, and myself played with it. While FTB is neat, it would be a completely different environment for the admins to work with because not all the permissions-related plugins work with FTB. Another thing is that FTB is known for being “glitchy,” and by glitchy I mean that there are ways to use blocks to go around some of the limitations. If I’m not making sense, take this for example: Explosions in your town are turned off, however someone created a nuclear reactor that can work around that and uses it to destroy other towns. Normally this sort of thing can be prevented by just disabling the blocks, but none of the admins are familiar with FTB so it would be a long, arduous, learning process. And the admins don’t have much time to play regular Minecraft, let alone Feed The Beast. I’ll still suggest it to them and see what they think. If you don’t hear back about it, just assume we are unable to do it at this time.