Melter and mixer centrifuge ember inconsistency

[gchpaco]

I'm an experienced Embers user and I forgot, again, that the melter needs the ember input on the bottom and the mixer centrifuge on the top, and got confused why things weren't working until I checked the codex. I don't know how easy it would be to make them accept ember from either the top or the bottom block, but it would be nice; there isn't any obvious reason for the restriction from a design POV, and it keeps confusing me.