I've been tossing around the idea of developing a limited line of NARROW, thru-hull, floor mounted FE motor mounts.
Design features include:
*1/4" Aluminum face plate with 8 couterbored mouting holes, allowing you to clock the motor into your desired orientation. Also doubles as a heat sink...
I also done both and had success with both. I've recently done some testing using a formed thread tap. IMO, I think they provide a tigher thread pattern in printed parts. The cut threads work, but they can have more runout when tapping by hand.