First, Bochs has released version 2.8. The release files do not include the USB Debugger, but the GitHub does. I believe there is a way to get the latest build using the actions tab, both *nix and Windows versions.
After doing some work with the Bochs BIOS, I found quite a few bugs and errors, so I decided to take on another project. Mostly just to see if I could do it.
It allows you to Boot a USB thumb drive via all four controller types, as well as many other enhancements, and even the start of a graphical GUI type 'SETUP' allowing you to change options, etc.
It is turning out better than I thought and has fixed many errors that were present with the previous BIOS. A release should be out soon as soon as I finish a few items and do a few more tests.
Since this new BIOS is written completely in assembly, of course I used my own assembler and found a few errors in it and added a few features to it as well. It was enjoyable to pickup that long lost project and add the fixes and features to it.
If you use or have used NBASM, I would surely like to know what you think.