I do it quite a bit.
My employer doesn’t care as it is not competitive.
I try to separate it as best I can. Send files from my personal email instead of work email. Setup my own account instead of a work account, but I usually pay cash and get the cash discount.
I have done this with our 3D print guy, laser cutter, machinist, printer, film guy, extruder and our vacuum-form guy. I have not made an IM tool, but I was close once.