Actually works, which surprisingly can't be said for some other addons for this purpose.
The credit cost is reasonably well argumented and seems related to actual costs of the models, not just a blind moneygrab attempt, making this the only extension I might consider paying for.
However the free tier functionality remains lacking. There are the free credits you get the first time which being a one time thing instead of periodic is essentially useless aside of as a paid plan demo.
There's also the "free" DeepL alternative which is always over capacity because it's shared by all users. The FAQ mentions being able to use your own API key but does not explain how and there's nothing about it in the settings.