Customizing MacOS guest VMs in Parallels 17 on M1

I've been waiting with bated breath for the ability to virtualize MacOS guests on Apple Silicon/M1, so when word spread that the Monterey beta + Parallels 17 made it possible, I ripped right into it. It works, but the official experience is definitely bare-bones. The UI doesn't currently allow any customization of an Apple Silicon MacOS guest, which combined with the default small-ish disk size of 30G, makes it difficult to do much "real" with it. The excellent Parallels APIs and command-line tools are almost completely unaware of MacOS M1 guests right now, so any Parallels automation you might have that works for Intel MacOS VMs won't work for M1 Macs. Thankfully, if you peel back a few layers, some customization is possible (including the disk size), and I was able to throw together a really basic ephemeral VM setup and cloning system with the couple of new M1 MacOS-specific command-line tools included in Parallels 17. Here's a link to a blog post I wrote with some of the details: http://blog.rolpdog.com/2021/08/customizing-macos-guest-vms-in.html