After days and a long weekend of mucking about with various guides with various levels of success, I found this post. THANK YOU
@pastrychef for this. It worked right-off. I've got a solid Catalina boot on one drive and then I installed Windows 10 on a second. Both show up in the neat little graphical boot picker menu.
Now I'm trying to launch the Windows drive in Bootcamp using VMWare Fusion (Pro 11.5.5). I'm getting a VMWare error "Boot Camp volume preprocessing failed." which, according to Google, has been around for a decade and might or might not be related to the fact that this is a hackintosh.
Has anyone run into this issue, or is anyone aware of anything special I need to do in order to boot a Windows drive in VMWare Fusion?