You're getting a little awkward mate.
You repeated yourself 3 times.
'Mate'.
Drupal is a tech I've used multiple times in the past for migrating DBs - I work as a dev.
It is by far the most malleable CMS platform in existence, and would completely solve the 504 errors. If you've something constructive to contribute to the tech suggestion here, please post it in one reply, otherwise 'it's awkward'.
