MacPro, APFS, Bootcamp Startup Disk Has anyone used brigadier to get a more recent Mac's bootcamp installer and extract whatever bits allow APFS volumes to show up in the startup disk selector in the bootcamp control panel under windows? If so what specifically did you have to do?

Details:

Have a late 2012 MacPro. It dual boots Mac OS X Mojave and Windows 10. In order to run Mojave the video card had to be upgraded. The Sapphire RX580 pulse is acknowledged by Apple as a working "metal" card and seemed to be popular so I went with it. The problem is it doesn't support boot screens. Not a huge issue until you want reboot from Windows back into Mac OS X on Mojave. Since Mojave automatically converts the install target to APFS there is no way to do it now short of zapping the PRAM or booting recovery and changing the startup disk that way. The lack of boot screens means no startup menu support when holding the option key.

I've done a lot of digging and I understand that newer Macs using bootcamp alongside APFS correctly show the OS X disk as a startup disk in the bootcamp control panel under windows. That is how I ended up with the question above- wondering if anyone has taken the time to figure out what drivers or what specific components in the bootcamp ESD for those macs changed and allowed APFS to work correctly with regards  to the "Restart in OS X" bootcamp option under windows.
Trying to get a "more recent Mac's bootcamp installer" is the wrong approach to take in a effort to solve your problem. Especially, since there are other ways to solve your problem which involve using the rEFInd Boot Manager. This free software is capable of instructing the firmware to boot Mojave.  

One solution involves creating a small 300 MB "Mac OS Extended (Journaled)" volume where rEFInd is installed. Here, rEFInd is configured to appear as a legacy OS X operating system. The Boot Camp software installed in your Windows operation system will detected this volume as OS X. When booting from this volume, rEFInd will automatically instruct the firmware to reboot to Mojave. This is setup to happen silently. 


  Note: The rEFInd Startup Manager executes silently and therefore does not require user input. 


An example of how to setup rEFInd as described is given as the accepted answer to the question: macOS partition disappered after installing windows 10 using bootcamp.