Most recent OS for 2011 iMac that will still work with Apple Photos

Hi all,

I have a mid 2011 27” iMac, Intel i5 Processor, AMD Radeon 6770M GPU

I’ve run this for years off an external SSD with High Sierra in a Thunderbolt enclosure which works fine, but took the time over the holidays to install a new internal SSD (old one had failed), so been playing around with OpenCore (mainly for fun).

Am very impressed. Ventura runs very smoothly, but Apple Photos doesn’t work (I think due to non-metal gpu?)

Does anyone know the latest OS that I could run where Apple photos would still work?

Thank you!