Downloaded and installed the ROM, running nicely
I did have a lot of issues flashing the stock ROM and TWRP/vbmeta files.
First Odin was handing on flashing super.img, but I used a different USB port and cable (as well as Odin 3.14.1_3B Patched from the Odin thread on XDA). I have been unlucky in the past with my S20+, with port/cable combinations, so I was ready for that...
The other issue was the TWRP/vbmeta files. I tried with the attachment in the OP - and others in this thread - but after flashing successfully I could only reboot to Download. That is, it wouldn't enter TWRP, despite Odin having given the OK to both the recovery and vbmeta image flashes. So I created this, making sure the files inside the .tar file werre recovery.img and vbmeta.img, and it finally flashed OK.
A poster described first compressing these files to lz4 and then tar-ing them, but that just gave me an file verification error in Odin at the beginning of the flashing process.
So, if you are having difficulties with booting to TWRP after flashing in Odin, try this file in the UserData slot