Short answer: NO.But can you also downgrade?
Can you move back and forth between these codebase types? I saw instructions to upgrade to the new license model. But can you also downgrade? This would make testing easier.
The extra functions will no longer work in the short term, I have experienced this before with a test server with the Redis function. enabled you will also see a downgrade version in CustomBuild.I can not say for sure, what issues can it cause and what challenges will you face, if you install a MariaDB version or start using other features not supported by a legacy license. I would expect them stop working as soon as you switch back to legacy license.
I think you maybe might be mistaken as it's said several times that downgrading from a modern license is not possible.If you want to return back to the legacy license, you can install the old key again.
This server was either installed or upgraded to a non-legacy code-base. Downgrade to a legacy code-base is not supported.
Servers using legacy products can seamlessly upgrade to the unified codebase by applying a new license key. However, downgrading to the legacy codebase is not supported.
I think you maybe might be mistaken as it's said several times that downgrading from a modern license is not possible.
To use the legacy license again, a full reinstall of the server would be required.