Joe, I never really had to change much to maintain tune going to two under. Maybe 1/16th” higher than before but all my toelkes are very forgiving bows even at different brace height, nock height, arrow material, weight, etc. Right now my upper nock height is 11/16ths above the shelf level. Used to be 5/8ths for a long time. My anchor is the same and my draw length actually is a bit longer with two under as opposed to when I shoot split, not sure why but it works for me. Never changed any other aspects in tuning and I’ve never had a problem with it until last year when I injured my middle finger at work, which takes the bulk of the weight on the string. After about a month not shooting, I used rubber tubing resistance bands to help restrengthen the hand, shoulder and back and ease the finger back into strength before shooting again. I started out shooting lighter weight for a while until it strengthened up fully. I did start and continue toying with three under as an ‘in case’ solution which takes some of the pressure off my middle finger, tho I know that won’t work for you. Hope all this helps and hope you can get back to shooting again soon.