I would really recommend to use English only or both, Rosetta stone way. That way you can edit (probably automated) translation to avoid language barrier mistakes. Otherwise I agree with you.
Declaring some mod as his even if he made it, actually wrong from TFP's standpoint, all mods are derivate content by their defiition. Asking payment is wrong too, at most they could have make donation system with parten\boosty, but donload must be free. Thing is then their imcomewould be based on people's opinion after the fact and they are inherently afraid of it 😛
From personal expirience with them - they not only constantly claim that people find issues "in old version" hinting that you should buy "new version", they also ban people from their DIscord for downloading mod and installing on their server (which also requires people to have mod locally). And it appears so that report any hosting that contains one of original mods or a pack of their mod for copyright violation. Not realizing that it causes ISP to bloack that website completely or tthat automated system would search and remove everything similar, how that happens with "Yandex Drive".
They do awful job at game balancing, mostly it's a game balance of "I have an opinion, I implement it." Withion regard of gameplay.
Localization both of this mod and on other other mods are down wrong, localized text is written down right where English belongs, by modifying original files (also a big no-no in modding community).