Follow up on this, I ended up doing it like Adrian's image in my other thread linked in the OP. I had more 2x4 than 2x6, so I had 2x6 under the feet (with holes drilled for them) and 2x4 across several other places. Lift with a fork truck and slings to get it on the pallet at the departing end. There were extra holes in the base, so I lagged it down with 1/2" threaded rod in 4 places then forked onto the trailer by the pallet. Pallet jack to get it set to the right place once on the trailer.
Bunch of straps, then drive home. Ended up with a tilt deck because a drop deck wasn't available. First time using a tilt deck, and I'm not sure how well the tilt damper works with a 2300 lb weight on the back, so put my floor jack under a corner and used that to control the lowering pace. Loosened the straps once tilted, some 3/4" black pipe under one end and a bar under the other to move it a bit, loosen the straps some more, and repeat. Once close enough to the ground pallet jack at one end and pipe at the other until all the way down. Pallet jack into place, and then a bar to get it lowered after disassembling the pallet beneath it.
In case anyone gets the idea to use 2x4 at the ends, I had it briefly on one 2x4 at the headstock end and one at the tailstock end. The 2x4 was visibly bowing. In my case the bottom of the 2x4 could only go 1/2" before hitting something else, so no real danger, but enough to show it wouldn't have been reasonable during transportation.
Turns out the VFD runs derated on single phase and the last owner had already used an L14-30 plug, which is odd since it was in a 3 phase setting, and clearly wired in the panel for 208 V 3 phase. So, swap the wire order to match up, and good to go.