I’ve found a viable solution, although rather annoying.
I have an external (external from the laptop) USB keyboard nearby, that I attached to one of my USB ports. I then attached that port’s controller to the StandaloneVM that I’m using to install Qubes OS in with this command:
qvm-pci attach --persistent {vmname} dom0:{BDF-address} -no-strict-reset=True
From here, I am able to boot the StandaloneVM with the Qubes OS installation disc and proceed to drop into TTY2 with the normal Ctrl+Alt+F2 key combo, using the attached USB keyboard, without dropping dom0 into TTY2, and being able to proceed with my work.
Until a better workaround is found, this method should always work in any case of needing to pass any key combo to any VM where the key combo would conflict with dom0.