Ha, nice to see someone do this properly rather than my proper bodge!
I didn’t use mine for long as I reckoned it’d trash the freehub, i figured id just order a one-up sprocket instead.
Whilst waiting for the new sprocket I switched to a 30t chainring instead of the 34t I was on before and that seems to be fine now – I never want for a higher gear and the climbs are fine (I live at the foot of snowdon so most rides included a fairly decent climb). I’m not sure I’ll bother using the 42t sprocket when it finally arrives.