By pure chance, saw that PHP 8.0 support was on a previous 'road map' for XC4. There's no such 'road map' for XC5 (that's available online anyway) so raising the question about future support for PHP 8.0 by XC5? Here is the PHP Support Schedule
for reference. The last change for XC5 in terms of PHP release support, was almost kept as a secret
Only found out about it via posts by other users on this forum. These were other users that had made the switch over to PHP 7.4.* and tested things themselves, in advance, then bug fixes were applied by XC and it became usable - but still via knowledge by accident mainly, not a timely official announcement as expected. New forum format, new approach to notifications by XC? Fingers crossed then!