Hi
If we can avoid migration I think that is the safest approach. I just had a failed upgrade (in current stable) and I'm guessing it can be a problem in other cases too.
Migrating through .sql files works, but please note that this can be a very disk and time consuming process. For small databases it is not a big problem but consider that databases can be many GB in size and in such cases the downtime can be considerable, and also it may not even be possible to complete it.
However if we do not have any upstream support, maybe we need to go this route. But in such case, maybe we need to check with our sponsors on what kind of databases they have and what kind of migration strategy is feasible for them.
// Ola