I've googled myself blind at this point and it still doesn't work, tried it with mode: 'cors' too, nothing
Ah, I see.
Getting slightly off topic now and I don't know if you're informed on this at all but do you have any info on why filtering hasn't been implemented?
It's been 6+ years now and aside from the ?exclude= thing people have consistently asked about it pretty much every year since. Does the backend just not support it? Is it low priority?