At the moment, we mirror production, which I think is 7.4.
When using CiviCRM today, I got this warning:
It made me think that we should probably be ahead of the curve locally....or catch up! The current prevailing thought is that we should mirror production and work on that, which I get, but this approach doesn't leave us much room to prepare the apps for the future. Sticking with mirroring production will delay our finding out what doesn't work until we are forced to switch.
We could have our cake and eat it by using PHP-version-specific branches of fundraising-dev that refer to different docker-compose.yml files which pull down different images. We could have a main & experimental split to keep it simple in the early days so we're not managing a bunch of old version-specific branches worrying about backporting the latest updates to them.
What do other folks think?