The off chainline doesn't help and neither does the 1/8 on 3/32 combo up front. Lube on the chain will quieten things down while keeping the chain at a good tension will also help.

What you can do is flip the bike or put it on the stand and listen to where the click comes from when you rotate the drivetrain - it may be coming from the chain when it goes over a certain link just to eliminate a kink somewhere.

Otherwise, that's just the nature. The lube should help.