Short answer: separating the language layer from firmware can reduce dependence on one firmware build, but it does not make every future version automatically compatible.
What “without a lock” should mean
It should mean that the owner is not forced to remain on one old software version only to preserve the interface language. It must not be interpreted as universal compatibility.
Checks that still matter
- Hardware generation and model suffix
- Current firmware branch
- Remote or physical installation method
- Backup and recovery options
After a firmware update
Verify the interface language, charts, sonar sources, networking and saved data. If the language is missing, stop and check compatibility before repeating installs.