Yeah QEMU's story for this sort of thing is pretty rough around the edges for OS dev. Wishing there was something like Unicorn-but-with-devices for making osdev tooling.
There's also panda[1], but I never got it working myself. I share your frustration, as it would help greatly with debugging, especially with nondeterminstic bugs. I likewise never got QEMU's record/replay to work.
[1] https://github.com/panda-re/panda