It's working well for me too. I got my first three cards in just before the last lockdown and since the reopening a few months go, am slowly building up my rounds with a combination of general play 9 hole and 18 hole rounds, and getting started in comps. 6 rounds in at the moment, so my lowest two are averaged with a further -1 adjustment.
Off that I've played a matchplay comp where I was given 12 shots; I won it on the first playoff hole so it was a tight game. I played a Stableford comp (95%) and got 28 points - slap bang in the middle of the field of about 50 players on a day the weather conditions were benign the rough was up, and I wasn't at my best. I've played informally a few times off my course handicap and got 30-34 points. I have had three friendly matchplay rounds - win 2&1 in one over 9 holes where i was given about a shot per hole, 3&2 in the other where I got about 12 shots, and lost one 2&1 where I got about 17 shots. So it seems pretty fair in that it is making for competitive matches and leaving me with average results as I am not playing loads better, or loads worse than it.
Ahead of my next matchplay comp round I'm going to put my 7th round in. If I play badly the worst that can happen is my Index will go up 1 as I will lose the -1 adjustment, my current third lowest will come into the averaging, and the round I play won't count towards the average, and it won't give me more shots for the forthcoming match. If I play well, index could come down and I'll get fewer shots; that's what I'm hoping for even if it means the match is harder to win!