I don’t understand why you don’t just upgrade to PHP8.
There are only a few things to do, basically add “ReturnTypeWillChange” annotation, add a few typecasts and remove the curly brackets around inline string variables.
Already done at GitHub “bohwaz:owncloud-core-php8”.
This fix is done in a few hours. Instead, you guys make Docker images and let specialized companies fix an outdated PHP version. I begin to think that you intentionally want to let classic owncloud die, just so everyone uses this “Infinite Scale” product.