Can't transmute excess schematics if you picked it up while already knowing it... Most of the time.

[Kain Yusanagi]

Expected behaviour: Pick up a schematic, it goes into the APE, and breaks down into herbs. (This happens some of the time; might be related to not knowing a particular catagory or not.)
Actual behaviour: Most of the time, extra schematics (schematic copies beyond the one used to learn a given tinker recipe) just get tossed directly into your inventory and cannot be APE'd. You can only hawk them to a merchant for a handful of gold. Can't even select them secondarily from menu to APE them, unlike any other item.

[Moasseman]

Not a bug.

This was an intended change. A really, really, really dumb one, but intended nonetheless.

[Zizzo]

Yeah, I eventually had to write my Schematic Recycling addon to reverse that change.