I regularly use the reporting facility on CM (Clozemaster) that appears with with every sentence, to report any original sentences or translations that not not appear to be correct to me.
My understanding is that any reported sentences are checked by a native speaker and he will make any changes that he deems necessary. Using this process is a great idea and can help improve the quality of the material on Clozemaster for everyone.
One addition that would be useful for the site would be a tagging facility, whereby any reported sentences that had been already checked and verified by the moderator could be marked by the moderator as such e.g. ‘Verified by Clozemaster’ or just a simple green ‘V’ sign, against both the original sentence and the translation. That way, users could have confidence in the quality of a sentence they weren’t perhaps sure about.
Best Wishes, Alex