The OpenCore Legacy Patcher, which makes it possible to install new system versions of Apple’s macOS on old, actually no longer supported computers, has been released in version 1.0.0 (meanwhile even in version 1.0.1 with a small WLAN patch). The 1 version makes it possible to install macOS 14 Sonoma on old computers.
For us, it worked very well on a MacBook 12″ Retina from 2015. And no, it’s not slower than it already was. Our procedure was to download the new patcher, let the patcher patch again, then let the update run normally and then post install the post install patch for the graphics again. Works fine.
However: a little research is recommended before. Usually everything should run smoothly on Macs from 2012, but there is no guarantee. On older models one or the other function may fail. So inform yourself here. When you are ready, download the latest version of the patcher from github.