think it sounds reasonable

It does sound reasonable but it sure would be nice to have tests to back up these claims. I have no way of verifying that this change is an improvement. He says that

it won't make any other side effect change as Spanish table does not have grade 2,

Does not having grade 2 imply you don't need lowered digits?

The nice thing if people open their own PRs is that you can get direct feedback from them :-)

There are people reporting that in grade 1 numsign is not shown preceding numbers, nor the hash sign. I suppose it's due to these changes.
https://groups.google.com/u/1/g/nvda-es/c/v6HIXIVaxTc
I am highly surprised on how this...odd report was accepted as the only proof of an issue, that is, someone sends a file through a mailing list and we suppose that the issue, that isn't clear at all by the way, exists without further investigation, and that it exists for grade 0, 1 and 2 tables. Does anyone really understand what issue was this person facing to propose this modification? Would expect Liblouis development to be more serious, specially given that it affects many third-party software, but...IDK.
On the other hand, the user says that Spanish doesn't have grade 2, and you have only to go to the tables folder to see that it's not true, Spanish as grade 2 since two or three years ago.
Honestly don't understand how this could have happened.

Specifically, this may have an impact on:

• BRLTTY
• Jaws for Windows
• Index Everest hardware
• Other software and hardware not mentioned here

This change is already visible on NVDA 2024.3, so it's too late to prevent it there and we must wait at least for 2024.4. That's one of the reasons we react almost two months later. I'll consider participating on the mailing list and take a closer look to this project.
This might be interesting also for you, @nvdaes.
Regards.

@ivnc , @jmdaweb it's not too late to fix it for the September release. Would you like to provide a PR to fix this issue.

Unfortunately I do not speak Spanish nor do I read Spanish braille, so I rely on good people that tell me on the mailing list or in issues like these how to fix/change the Spanish tables.

What would really help to prevent this from happening again would be test cases in the form of YAML tests.

@ivnc Unfortunately these kinds of mistakes can happen. As @egli says, the good thing about this is that the test suite will become more robust after this issue has been fixed, so it's less likely to happen in the future.

@BueVest Oh, I thought the PR was a work in progress.

@ivnc , @jmdaweb can you open an issue about this and even better fix it in an PR? Thanks