If ever needed, to cripple updates in Opera, in the "autoupdate" folder in Opera's install folder, rename "opera_autoupdate.exe" to "opera_autoupdate.off". Then, in the Windows Task Scheduler, disable all of Opera's autoupdate tasks. Then, block Opera's autoupdate servers.

Then, monitor https://blogs.opera.com/desktop/ for new versions and download and install the new version when you want. Then, repeat the disabling of opera_autoupdate.exe and the autoupdate tasks.

There's even an RSS feed for that page you can subscribe to at https://blogs.opera.com/desktop/feed/. You can even follow https://social.vivaldi.net/@browserversiontracker on Mastadon to see when a new version of Opera one comes out.