Sadly, Realbooru owners just don't care and that's the reason ¯\_(ツ)_/¯
I bet that if they would make Realbooru's code open-source, then dumb things like this and API would be fixed in max few days... But that ain't gonna happen either, because they would have to make an efford of excually do something...

That would be the best option but they won’t do it because the software they use is closed-source licensed software. The only thing that might help Realbooru is an update from 0.2 to 0.3 or a complete rewrite of the whole thing but in all likelihood neither of those things will happen and they’ll just keep farming money from ads. An imageboard for real porn has great potential for archiving and so on but this site is barely usable