Finally caved and decided to remove the 10-Speed Microshift and other AliExpress parts and source more period correct parts for the bike, namely an XT groupset, half of which I stole off my Cannondale Super V (which I’ll upgrade to XTR over time), and the rest I sourced on eBay bit by bit.
Really happy with how it’s turned out! Shifting is so much better now, it all just looks and feels so much more right (to me!).