Currently LibreELEC-RPi4.arm-9.80-nightly-20210226-e12ff43.tar 2021-02-26
A couple months I am upgrading almost daily, the first upgrade was over LE 9.2.6.
There are still some issues, like with timeshift, but I never had an issue which should prevent TVheadend backend from starting.
You can perhaps also try to install Tvheadend 4.3 from ,zip ( Tvheadend nightly builds for LibreELEC ), I did not try yet and I am still running 4.2 which is part of LE 9.80 Nightly.