You can build a custom kernel fairly easily. The patch at
http://lists.infradead.org/pipermail/linux-nvme/2019-December/028243.html seems to only affect a builtin file, so if you build our 5.4.3 version just with that patch, you don't have to build the modules, ours will work. Then you'd replace our vmlinuz with yours.
Some specific vendor's drives being standard incompliant is not really a big enough issue for TC to update the kernel mid-release, though. Especially as it's nvme, not very many TC users with such hw I think.