Planned setup migration help

I would like to ask your comment on our planned setup for migration.
We have a backup (non-Discourse) .tar.gz file and will restore it in our QA server — so it points to the QA RDS database. We will then install themes, change site settings here so it will get saved in the DB, right?
After initial setup on QA server. We are planning to create a snapshot of the QA RDS DB and restore it in a new database in Prod. We have Prod setup in ECS with Discourse installed already. We are planning to build a new image that points to the new database (from QA).
Is this ok? Or are there complications with doing snapshots and pointing to restored databases? Or should we restore directly to Prod?