Late to the discussion, but here's something I've done when needing to get some more threads in an already-threaded thin piece of material...
1. Tap plate
2. Grease bolt, run through plate with some stickout
3. Apply epoxy to back of plate
4. Thread bolt in motor hole.
5. Rotate plate (only) until it is drawn down to motor surface and clocked where you need it, but is not trying to pull the bolt out like a jacking nut.
6. Clean up epoxy oozing out
7. Remove bolt after epoxy sets up.
The epoxy 'shim' will automatically permit the plate & motor hole threads to be timed.
Optional - pin plate in place if there's any rotational loads expected after epoxy is set.