Hello,
Updated from PB 3 to PB4. Must say that it works quite good for this website.
Only 3th party plugin/extension installed is Akeeba backup so far. Joomla 4.2.3 / Helix latest version / PB 4.05. I haven't made big changes or edits yet but for now it all looks good. Did it with a backup using a local machine running on PHP 7.4.
Good the idea when updating from PB3 to PB 4 the trick to avoid errors is to have installed as less 3th party extensions/plugins as possible.
When does Helix /PB fully PHP8 compatible? Next month support for PHP 7.4 stops.