onthefly,
If it smoothed out when you put it in a nose-up attitude you may be running it too rich. That coupled with the idea that diesels run cooler may mean that you are not getting the ABC cylinder up to proper running temp. This COULD cause excessive wear.
I would suggest adjusting the needle to max, readjust compression, etc. until you find the optimum settings. Don't assume final settings until the engine has run a couple of minutes to warm up properly.
If the starter works for you, by all means use it. Just be careful of hydraulic lock. It is a good idea to flip the prop before applying the starter to prevent damage.

George