I went through this with my boat, which I installed myself. It was the first time that I had fitted out a boat. I had the same problem with a list to port. For a time I improved it significantly by adjustment of the trim tab (yes I know this is contrary to theory), but it was not consistent and I knew that I still be an issue. My engine is offset by 1.5 inches.
I have two batteries, a light weight starter battery, and a much heavier house battery. I had installed these to the port side of the console. So I removed the old battery holder and fitted the batteries with the heavier house battery as far to starboard as possible, and the starter battery close up beside it. With both the batteries offset, and the engine offset, the torque reaction of the engine has been overcome, and I have since had no problems.
The point is that even with a decent engine offset, the installation in your particular boat could still be an issue. Look for weight that is offset to port. Check and be suspicious of everything; if you bought the boat second hand you probably have no idea what has been done to it in the past