* If you upgrade LÖVE you lose all your local apps and their saved settings.
This includes code changes. It's hard to get code changes out due to mobile
restrictions. I can't come up with an alternative to copy-paste. This
imposes a strict limit on the number of changes I'm willing to make to a
large app on my phone.
* If you upgrade such apps after making local changes to them, you might see
strange errors. Local changes are written to an overlay directory, whereas
upgrades modify the app in place. The two locations create lots of
opportunity for conflicts to arise.
To mitigate this issue, such apps by default list local changes in the
output editor every time they run. That will hopefully act as a reminder.
There's also some helpers for deleting local changes in the 'scratch' page.