> among other things, all the Emacs versions I've tried (stock GNU Emacs or Mac Port, downloaded binary blobs and compiled on my machine) are either immediately unusable or become so slow after a day that they are almost unusable.
So basically my #1 work tool will no longer work.
That’s a hard deal-breaker right there.
As a longer-term means of escape, what’s the best way to run a «full» Linux desktop on a otherwise managed Mac?
Parallel or Vmware (the former is paid and the latter is tortuous to download). Then you can go with debian (for minimal installation) or fedora (for ready to work desktop installation). Works quite great.