Not to say that you are wrong for your particular use of the technology, but my take on the subject is different ... and I am not a big fan of biscuit joinery in furniture, but I do like to match the joinery to the task.
IMO, biscuit joinery is NOT a precision operation at its highest level, even with the Lamello, which I've tried. The 557 is much more than adequate for the job, and the FF blade is quicker to set up than a slot cutter on a router table, just as accurate, and a damn sight faster ... done it both ways too many times to count, and I routinely use a slot cutter to cut spline slots. And a biscuit that has to be tapped in with a mallet is much too tight, IME.
Just glued up a small (12" x 28" x 1 1/4") table top this afternoon, used #20 biscuits and the 557. The biscuits, with glue on them, were snug, but could be pushed in by hand with the same resistance you feel on a well cut mortise and tenon joint.
Just my experience/tuppence ...