I make cope & stick doors on a router table (no power feeder) and often fight splintering when making the rail/stile groove cuts. I've tried changing the spindle speed and how fast I feed the board. Same result.

I've been thinking for some time about making a VERY shallow climb cut on the first pass...maybe 1/64? I haven't tried test cuts yet but am thinking breaking the surface might reduce or eliminate splintering when routing the full depth groove in the proper direction. Anyone tried this? I'm well aware of the dangers of climb cutting hardwood, although I routinely climb cut a 1/4" groove in plywood to receive the cabinet back.

There was a guy here a few years ago who said he routinely used a power feeder in reverse to climb cut on his shaper with excellent results.