in theory you can fix the issue at the sacrifice of higher tier furnaces. you don't really need them if you're using the full bob suite, as you'll have the chemical mixing furnaces.
disable 5dim
go into mod settings
in the "Bob's Assembling machines mod" section, turn off furnaces
re-enable 5dim.
Should work.
I did look into the issue, but personally, I'm not going to make the change because the fast replace group on the electric furnace is set by the base game, and there's little point in using anything else because it won't fast replace with the stone or steel furnace anyway because of the size difference. If I did go and change my furnaces to use 5Dims electric-furnace group, it might break compatibility with any other mod doing anything else with furnaces.
So in short, I'm saying it's 5Dim's fault for breaking convention without any real reason to do so. (Even if it did let you fast replace a stone furnace with an electric furnace as a result of not changing it, would that even break anything?)
