So I’m tempted to replace my trusty old 2013 13" Core i7 MBP with a new 14" MBP if/when it’s released. Obviously that will push me from Mojave to Catalina. I’m sure I’ll eventually be able to deal with that (lots of my work stuff is compiled from Linux source so probably some recompiling there, should be doable). It’s likely not going to be a picnic, but considering how much time I now have with the shelter in place order and campus locked down I figure this would be the right time.
The real question to me though is what I’ll do with my old 13" MBP. It’s running Mojave now and I’m perfectly fine with that. I know though that there’s several older apps I have that won’t run on Catalina and I also seem to remember they ran better on High Sierra. None of that stuff is super important, some are games, others are just for nostalgia so nothing I’d spend effort on to get running under Catalina in a VM. Instead I’m thinking I’d probably like to — once the transition to the new MBP and Catalina is complete — downgrade the old Mojave MBP to HS. Now obviously I could just nuke the old MBP, install HS, and then attempt to migrate some of my old stuff, but frankly, I’m too lazy for that. What I’d like to try is to install HS over Mojave so I get a brand ‘new’ macOS but retaining my installed apps, user home, prefs, etc. Now I realize standard MA installs work if you’re updating to the same version or a newer version of macOS, but IIRC you can’t straightforward migrate to an older macOS. But is there a simple way to get around that, like deleting macOS and having only that part installed from scratch so I retain apps and user space?
Any advice on going that route? Can that work? What’s the least hassle way to get it done?