I know this was talked about in the discord chat briefly, but thought I'd put it here so that it was remembered if there was any question about it. There are a couple recipes that enable duplication (for a little bit of rf so....take what you will from it) Three recipes I've seen so far:
Blaze rods: squeezer gives 6 sometimes 7 blaze powder, 5 can be used to make a new blaze rod
Wool: squeezer gives 6 string, 4 needed to make a new piece of wool.
Quartz: Gives 2 crushed quartz, smelt each to get 2 quartz.

Whether or not these are an issue I don't know, but thought I'd consolidate the info in the chat and verify it.

Blaze Rods give 5 Blaze Dust. Tested in a whole stack and it was 5 everytime.

Quartz gives 1 Crushed Quartz.

Wool does indeed give 6, will look at changing this recipe.

Thanks for the heads up.