For context, I’ve verified that the Haiku live usb is fine, and the laptop in question can load linux just fine. I’m running coreboot with a SeaBIOS-then-grub payload, on an old core 2 duo thinkpad. Something doesn’t add up here, though, since anyone running Haiku with QEMU would be using SeaBIOS too, wouldn’t they?
Welcome to the Haiku community!
I don’t know about SeaBIOS but booting Haiku from GRUB2 definitely works. I’ve dual-booted Haiku with Ubuntu and Linux Mint in the past. But I don’t have my configuration around anymore. Just do a search on the forum with “GRUB2” and look at the more recent threads. You should be able to find a working config there.
Sadly the configs I’ve seen either aren’t applicable, or don’t work for some reason or another. Chainloader and boot on the live usb’s efi just yield “unrecognized payload type”. All the grub discussion I’ve seen was for an already installed haiku instance, not booting the live usb in the first place 
Sorry, I must have overlooked that you are having problems booting the installer and not an already installed instance. I can’t help you in this case but maybe someone else from the community can.
You could also check the bug tracker at https://dev.haiku-os.org/ if there are any tickets related to your problem
What happens, specifically, that doesn’t work?