I've read a few posts on the flox thread suggesting that people successfully did a dirty upgrade from the unofficial rom (having repartitioned in the past using clamour for unofficial ROMs) they seem to indicate the opposite and all that was required was:
1. Flash the TWRP flox recovery
2. Flash official flox signed zip
3. (Possibly optional) Flash LOS flox recovery if you want to use the internal updater to automatically install downloaded updates.
So is the above possible? I'd rather not have to reflash magisk and do a Migrate backup just to move to the official build which only seems to provide SELinux support above this one. AFAIK it can't repetition without erasing all existing data. Netflix and a few other things were working on the unofficial build when I last checked although I don't use them on here much anyway so not quite sure what advantages the move to official actually would bring. Are the unofficial builds going to stop which will make this necessary?.
The unofficial is built on a 1.1G system partition.
The official is built on a 1.5G system partition.
The stock partition table for flo/deb.
Pastebin - Link
To be safe, a lot of us only used system, cache and a bit of unallocated space to (re)partition.
So we have a 1.2G to 1.3G system partition depending on how we did it.
Clamor's script to (re)partition is a more complicated.
If you use that method, you will have a 1.5G system.
Along with creating vendor on partition 30.
Then adding partition 31 for userdata.
The official install instructions use Clamor's partition script to prepare the device for install.
LineageOS flox Wiki - Link
If you used Clamor's script to (re)partition then you should be good to flash flo(x) without having to partition again.
Not sure what the difference is between the official TWRP and TWRP for flox is.
I am guessing it is based on the UA TWRP so it has support for the new partition layout.
As for switching from unofficial to the official build (as long as you used Clamor's script originally), the only problem would be build signature.
Not sure how pitrus- was signing his but, I assume the official is using LineageOS's signing key.
The TWRP for flox very well could allow you to update a rom using different signing keys.