my PI is still in version 10
Hi, it's RPi, the SD card can be swapped in seconds. If your RPi it's working well with the LE10, remains the question if you want or need to upgrade or not. Otherwise you can grab an another card and try the new LE. It's need some time till all settings and addons resolved, but if you have the old setup on another card, anytime you can switch back to the old the version.
With TVhead it is complicated...
I seen here how can be moved the TVheadend 4.2 setup to TVH4.3, didn't tried. Otherwise a fresh setup is always better, and to spend some time once after few years, I don't think to be a too big sacrifice.