[dominicperry]

I'm not completely clear about what you have - you say you have two machines, but only list one. Are they both 2019 MBP's? Do they both have Catalina?

What you run should partly depend on what you want to do, where you store personal and valuable data and whether you need to transfer work between one and the other.

I have a Mac Pro 7.1 running Catalina and an MBP M1 Max running Monterey.
I like being able to boot the 7.1 from an external cloned disk which you can only do with Catalina. But due to the age of the OS, I don't store any personal or financial data on that machine. I keep my M1 up to date with the latest version of Monterey because I use it for banking and it has lots of personal data on it. I do music on both, use the same version of PT and Reaper on both, and only Logic gives me problems with different versions on each, which is hard to fix. Carbon and RME work on both.

I only upgrade one at a time (true for both OS and PT) - leaving it at least a month before touching the other one.

Not sure if that helps, just a reflection of my approach.

Dominic