Followup post has it figured out. I code initially on the SnowMeow laptop, so I can have retro AUs and VSTs: that also runs an old Parallels which runs a Window

Followup post has it figured out. I code initially on the SnowMeow laptop, so I can have retro AUs and VSTs: that also runs an old Parallels which runs a Windows VM and a Linux VM, where those VSTs are made. All that stuff is old, the laptop's air-gapped and never talks to the internet, and I bring the code over on an SD card to the Mac Studio where I do the signed versions of AU and VST, make the videos, etc. I also resist 'latest versions' of things quite hard. Generally that's not what I want. I want stuff where it's working consistently. Even my web browser is a Chromium picked specifically so I can be sure it will get old and go out of date until _I_ have a reason to change it, which will doubtless happen but it'll happen when I want. I can't imagine running Snow Leopard but also feeling like you have to run the newest of everything. It can't even run a remotely current web browser. You have to already have programs that will be exactly what you want and need. Then, you use those and get used to them, like cooking with an old chef's knife you've had for decades :)