We just don't use lifters at all anymore since the knife is already nice and close to the dirt. I think a 6-bat reel would pull in flat peas rather well with the FD75 and no lifters, especially since the reel can stay in close to the knife even during flexing. We've found that cutting at an angle to the seeding rows (sometimes taking into account the overall lean) works well. Ours is 5-bat but we've often thought 6 would be slightly better. Our D60 with 6 seems to work well with lodge crops, maybe feeding slightly more evenly.
 Seems like a lot of lifter designs are meant for the old auger headers where the knife was never that close to the ground. Our lifters would actually push up when we sit the FD70 on the ground, so they weren't effective anyway, except at pushing dirt and providing places for the pea vines to bunch up.