Just used OCLP to go from Catalina to Monterey on a 2013 iMac 21.5’ after upgrading the SSD myself. Works amazingly!

Was having issues with certain games/apps on Catalina and thought I might as well give OCLP a go after having replaced the slow 1tb HDD with an SSD, turned out to be way easier to install and sort out than I’d have thought and works a charm with no issues to report so far on a 2013 iMac 21.5’ (qc i5, 8gb RAM, 500gb samsung ssd)! Chose Monterey over sequoia/sonoma as I’ve heard that they can be a bit worse performance-wise and something to do with Metal graphics support? Either way OCLP is amazing and has saved yet another iMac.