That is, electric furnace slot, generator fuel slot, all generators battery slots, input and output slots in macerator, compressor, extractor, etc etc. I know, there are automation mods and stuff, but not everyone has or like to use them. Not to mention that interaction with them are often bugged, like with last update. And there is nothing industrial in machines that should be fed stack by stack (or in some cases, item by item), like some lowly vanilla furnace.
Thaumcraft2 has it, and it works great - http://technicpack.wikia.com/wiki/Arcane_Furnace. Not to mention some Forestry machines.
.
