r10tnrrrd

This is a good tutorial article, but in my experience there are some caveats.

1. Unplug everything you can before starting.  USB Webcams, UPS USB cables, etc.  Only plug in a wired USB keyboard & mouse, plus the USB stick (if you are using a USB stick).  Don’t use USB hubs, etc.  Keep it simple until after the OS install.  Then you can re-plug everything back in.

2. I had no luck using USB 3.0 USB sticks.  I ended up using SanDisk Cruzer Glide (16 GB) USB 2.0 sticks and they work fine.

3. I found ‘fancy’ video connections often didn’t work.  Thunderbolt video or mini DisplayPort connections would leave me with a black screen.  I had to fall back to basic HDMI connections to get things to work.  The good news was that you only have to put up with the lower res connection for the installation phase.  Once you install Sequoia (or Sonoma, or … ) you can shut the system down, switch to the higher res connection, reboot and it will work.  I also recommend using SwitchResX to enable more resolutions/modes in the display.

4. After OS installation is finished, you might run into issues on certain platforms with Chromium-based browsers.  MacRumors’ Forums have workarounds.

There might be other gotchas in the installation, but these are the four that I remember most.  I’ve successfully used OCLP on two different 2013 “trash can” Mac Pros so far, and am about to try it on a 2012 Mac mini that is currently on macOS Catalina.  (It has a non-SSD boot volume so it’s pretty slow.  Will be interested to see how performance is after installing Sonoma.)