Is it possible to make a mbr legacy bootcamp win 10 from a gpt partitioned catalina hdd 10.15.7 with bootcamp 6?
Using the boot camp assistant, loading a usb 2.0 usb stick with the iso and drivers, partitioning the drive in boot camp assistant, then letting it reboot into the usb 2.0 installed windows fine on a 2012 macbook air with all windows functionality.
no need to mess around with efi and weird workarounds to get audio and having screwy drivers.