OCEAN mining pool have just announced lightning payouts (https://ocean.xyz/docs/lightning).
The instructions require to sign a message containing a BOLT12 lightning invoice which is usually a very long string of characters with no white spaces.
When trying to sign he message with Seedsigner version 0.7.0 i get on screen an error:

TextDoesNotFitException
components.py 1398, ...

It seems that the exception is raised not because the device is not able to sign the message, but instead because it is unable to display it on screen.