If you are eager to get started and do not want to wait for 5.2.4 to be released, then “Yes” you can try a 3.2.6 version (covering the 3.0.x to 3.2.x versions of Gramps from that era). It still used the Schema 14. So you can sidestep the issue updating schema 14 to 16.
With any approach, the first step is to make a copy of the database folder for Gramps. Because every time the database is touched, the database backends update the file with an update to the connection history. Each experimental touch means a chance of corruption.
Once you backup and install version 3.2.6, set the database location (here is the Database Preferences docs for the 3.2 family), load the tree and export to the GRAMPS XML database format. Gramps 5.2.3 will be able to import that into a new tree in the modern SQLite database schema.