VBox 6.1.0_RC1-135185 dev snapshot for the upcoming 6.1.0
VBox 6.0.15-135093 test build for the upcoming 6.0.16
With the setting VMSVGA the boot process still hangs. With VBoxSVGA (or the old VBoxVGA) it works.
I don’t think that will change as long as vboxguest modules are integrated in the image. To my knowledge with kernel 5.4.x this is no longer necessary.