You give me too much credit, PowerPanda, all I did was insert a bypass into the shop routine so that we could use sprites other than Merchant and Imp. User "Myself086" wrote the Gogo scrolling code and you straightened out all the other details to expand Hatzen08's Guest Adder.
ReCast doesn't use FullRoster in its entirety, though, I was too far in development before it was finished. Instead, Strago got moved to Gogo's actor slot and Banon took actor slot 7. In fact, in an earlier build Strago didn't have magic at all: he was using party magic until I found GrayShadows' work on Gogo from the 15th man project.
All that said, I hope FullRoster will have a fruitful life in the FF3 hacking community. I'm secretly crossing my fingers that Iris Havengard will get another shot. I'm also hoping the randomizers will adopt it, since two extra actor slots would open a lot of possibilities.
Getting back to the discussion of incidental characters, I do have some fun with Biggs, though fun is a relative term. I don't want to spoil too much, though... let's just say the banquet is more interesting for his presence. Another incidental character who gets an extra nod in ReCast is the surviving Doma Sentry. Were I more ambitious I suppose I could have done more with him; his use here was convenience of continuity.