Addons not ready for PHP 8

The add-on for the full-page background is not ready for PHP 8.

This may apply to other add-ons as well. Mr Dillington is not responding to requests to update posted on Github. Can I add a repaired version to my theme package? I hate to see the marketplace become stagnate with a lot of broken add-ons.

That depends on the license. If it is MIT you can do what you like. If it is ‘Concrete Marketplace’ you need the developers consent. If it is GPL, that has implications for your own license.