Now in order to get gapless encoding to work, that instance of LAME has to remain running while EAC is ripping, and you can have no more than one instance of LAME running.
No. For gapless encoding to work, all the files must be specified on the same Lame command line. EAC can not do this, it always runs Lame individually for each track.
Incidentally, Lame 3.91 disables VBR tags if --nogap is given. This is unnecessary, and should be commented out (in frontend/main.c) if you'll be using your gapless files on an Empeg.
Peter