I can't seem to find it but I thought I remembered reading that due to ram limitations some compromises had to be made are their any features that are lost with the flex fuel maps?
Yes but you won't miss them. Fuel scalar, afr etc becomes single tables instead of banks (tbi cars might cry foul), multispark is bye-bye, one load to torque table to rule them all, some unnecessarily large tables were shrunk to useful size etc. The ROM is definitely reorganized for flex fuel, and despite not containing the actual logic changes that are written at flash time by MHD, these ROMs are effectively not I8 or IJ anymore. Should probably be referred to as I8AFF and IJEFF now or something since they will need special xdf, and they cannot be properly loaded without MHD.