Personally, I decided to go with an APE copy from China, less than $30 as I recall, postage included, and impeccable quality. The key to manual adjustment is to roll back the oil seal O-ring on the threads so that it doesn't add to the friction of rotation. I would estimate that this is at least 90% of the net force required to turn the adjustment bolt. No exaggeration. Once you do this, you can finger-adjust the tension with great precision. I haven't put any real mileage on the bike since then, but the plan is to run it 50 miles or so, then readjust to a firm finger-tightness and no more. Maybe check it again after 500 miles or so, then every 3,000 miles or once a year thereafter.
Any thoughts on my proposed maintenance schedule would be most welcome.
I think if you check it at 50 miles and it doesn't need adjustment, you can go to checking it at your next oil change and then depending upon how much it needs adjustment, then decide on a period of scheduled maintenance