Subject 2.5.1 upgrade dilemma
I have several hundreds of Firebird installations out there that use 2.5.1. Because of features added in 2.5.2 I updated my setup to install the latest version, 2.5.4. Now, after a small amount of those installations have been updated, I noticed the warning in 3.5.3:

"Warning re Databases Created or Restored under Firebird 2.5.1

All users upgrading from Firebird 2.5.1 to a higher sub-release are strongly advised to migrate databases using gbak backup/restore. If this is impracticable, at least rebuild all compound indices in the databases being migrated.

Databases being upgraded from older Firebird versions (ODS 11.1 and lower) or v.2.5.0 are not affected by this regression."

Since this update turns out to have a much bigger impact than I expected, I'm wondering what my best option is when I have to choose among the following:

a) Reverting to 2.5.2; still has remote backups via the service API (the part I needed to upgrade for) but behaves similar to 2.5.1 so the database can remain untouched for now. Some security issues, but none of these databases are connected to the internet.

b) Going through with the update to 2.5.4 and rebuilding all indices.

Rebuilding the indices is not the issue. It's just that the warning implies that rebuilding the whole database is really better than just rebuilding the indices. Am I still at any kind of risk if I just rebuild the indices? What is the worst thing that could happen?

Also, what is the worst thing that could happen to that couple of databases that are out there now running 2.5.4 while created on 2.5.1? Am I still in the clear if I take action now, or could some kind of data loss have occurred now?