Do you fix bugs after an OpenCart 3.x upgrade?
Yes, post-upgrade fallout is a big part of what we fix. Moving to 3.x (or onto a new PHP 8 host) often breaks a theme or extension that relied on old behaviour: Twig template errors, undefined-index notices, broken OCMOD modifications, or a payment module that no longer matches the new API. We map what broke, fix the templates and modifications, and bring extensions up to the version they were built for. This usually fits a Bug-Fix Sprint.