We have RE and FE integrated and Fund, Gift Type, and Gift Subtype are the only fields that translate into coding in FE from RE. Our RE fund links to a project and then we need to differentiate coding based on if they are giving to this Fund/project through an event fee or just unsolicited through our website form. If its through a specific fundraising event we need it to go to a fundraising revenue code rather than just a regular donation revenue code. I think you could assign this in the Fees are of the events page just like you assign a Campaign and Fund.
We just remapped our FE funds according to best practices and use gift subtype for most credit card transactions. I'm currently manually entering gift subtype for all online gifts.