One thing you have to watch on the MSD models is a bad ADC board. When this board starts to fail, besides skipping the defrost cycles later on, will begin to short-cycle the compressor. I have walked into a home and heard this board chattering away, causing the lights to flicker, etc.
If you are sure that compressor is not on the way out, look for a new adaptive defrost board soon. I'd still put a hard-start on the compressor to be sure.
You never mentioned monitoring the voltage during startup, which I am sort of disappointed in you for.