Upgrade from 4.4.13 to 5.2.6 cannot finish

I agree on the prefix removal. Or at least let the sql driver handle it so when you run
$schema->getTable('xxx') and a prefix is configured, it would automatically get the ma_xxx table. I think this is how Drupal does it, when you use its Database API.

Moving on to more issues of the upgrade

For this topic scope, I only have the following yet to be answered