I use RP to sort the common items and anything unsorted by RP falls to the default chest, which doubles as the input chest for LP, no reason you can't use both.
Exactly. I'm trying to noodle out of there's a way for RP to handle my fermenter better than LP. Right now I have a hopper dropping into my fermenter. I have it set up to be feed reeds, cactus, wheat and saplings. The problem is that I want to cycle through those inputs but not get stuck on any individual. Right now with the hopper if the first slot is free anything that matches what is in the fermenter it will fall right through, causing the system to request more. I kinda ran out of saplings and seeds once until I hit the bright idea to have the farms ask for 16 with partial requests while having the fermenter request 32 without partial requests. I'd like to replace the hopper with an RP machine but for the life of me cannot think of what might be better. A sorter off an inventory would get jammed if I set it to require each input before proceeding whereas it would do no better than a hopper if it doesn't. Managers would work but that would require me to run tubes in line with my existing pipes.
LP also works well with RP relays so you can reverse the process, I route all my unprocessed ores through LP to a relay since pneumatic tubes can find the nearest empty macerator much more efficiently.
I just dropped a hopper on my pulverizer. Sure it takes 2 pipes instead of the normal 1, but I found that TE doesn't play well with extract modules anyway. The upside is that I have 5 slots and rarely overflow. Or, if I want to manually inject something into the system I just put my item as next in the hopper, pop the item in the pulverizer out, then place it back in the #1 spot in the hopper.