It's probably way late to chime in on this subject, but just in case you have not gone to the unsupported MacOS, here are some hard learned lessons.
The patcher is a great tool, and provides fairly easy access to the later MacOS versions. The things I think casual users need to know are the following:
When Apple releases new OS versions, they also might include upgrades to some applications and their data that many users take for granted. Examples are iTunes and Photos.
Going to Catalina, the Photos app "upgraded" the entire Photos library. The problem is, if you ever have to go back to High Sierra, that new library is not accessible. You cannot "downgrade" it.
iTunes basically went away, being split up into several different apps. Trying to piece the new files back into the old iTunes on High Sierra was a real treat. So, my solution each time I have tried using the unsupported MacOS tools is to save a bootable version of the old system, using a tool like SuperDuper.
The other problem I came across is that the built in MacOS update now in the App Store app no longer works on an unsupported version of the OS. To keep your OS up to date, you have to wait for the source of the patcher to issue a new version of the patcher, and install it again. Now, maybe smarter users than me know how to do this without having to backup all data and applications, and then recover them after the new installation. If so, please share. If you are really concerned about privacy and security, you want to keep your OS up to date, and it is the update feature that does that for you.
I really enjoyed testing out Mohave and Catalina using the patcher, but finally decided to return to High Sierra until ready to purchase an up to date Mac. Waiting on the release to the much talked about Macs based on the Apple silicon.