MP 1,1-5,1 MacPro5,1 upgrading AFTER dosdude Catalina upgrade

[Al'sMacPro]

Years ago I updated my MacPro 4,1 to 5,1 then upgraded to Mojave with tsialex's excellent instructions, and installed a flashed RX580 GPU. More recently I went to Catalina via dosdude, as that seemed like the simplest path. It has worked flawlessly, but now Catalina's a bit too long in the tooth, I can't get updates to Chrome, etc, so I want to move on.
It appears that I can move up to Monterey or beyond (??) using either OCLP or Martin Lo's method, but as I am a dummy the former is probably going to be the way. And from what I'm reading the dosdude patches won't be a problem, and I should not need to downgrade to Mojave.
Before I start on this little journey I'd welcome any advice or cautions. And please, speak to me as you would to a young child, or a golden retriever. Thanks!

 

[Bigwaff]

And please, speak to me as you would to a young child, or a golden retriever. Thanks!

First, verify you have firmware 144.0.0.0.0. If not, get there. Second, using supported macOS (High Sierra or Mojave), download OCLP and build macOS USB install media (either flash drive or another internal SATA drive). Follow the very detailed instructions on the OCLP documentation web site. Boot macOS and migrate/copy data from your Catalina drive. There are numerous web tutorials and YouTube videos which will walk you through the entire process... as if you were a young child. Young children want their hands held. This the place for questions and help, but not hand holding. You will need to put in the effort by reading and watching first. Good luck!