My ID.4 First Edition went in and upgraded seamlessly. There was a delay getting it back as I had asked them to do the light bar on the tailgate too and the part did not turn up for two days. There are many stories of the upgrade going well, so don't fret too much.
I hope it does go well - My concern is pretty justified (unfortunately) when I took the delivery, afew days later - it was throwing up errors and lit up like a "Christmas Tree" ! With "Stop driving", "Engine faults", coolant low, displays going "dead and blinking", Sat nav would cease to work for a day, Audio would stop, the dealer who sold it to me - vanished and didn't respond ... Head office were useless ... and it took some effort to agree to them to ask my local dealer to look at it ... but when it kept going into the dealer the Faults/Diags showed nothing - but the pictures (and video's) I took proved it had "issues"...
I ended up becoming friends with the mechanic (who at the time was only just starting to get some ID training) - who I would show the pictures and video's each time it went in - to demonstrate the issues. As he said "he was learning with my car!"
VW Head Office were useless, the Dealer (although they tried hard) had no support the ID range was new to them, VW breakdown could help (the AA couldn't even read the OBD port) ... it was only after 6 visits to the dealer the car started to "stabilise", I had their ID.3 loan so frequently they should have given me a key and put me on the insurance !
The current version of SW that was delivered OTA - hung and took a day longer than it was mean it (apparently).
So I'm sort of guarded and cynical this will go well !