I once had a fairly heated argument with other teachers over tag questions. Students were Singaporean, inclined to come up with things like "You would like a coffee, isn't it?"
Lots of languages have a universal tag -- Chinese ma, Japanese ka, French n'est-ce pas, ... English doesn't; there's quite a bit of grammar you can teach about tags. There are exceptions to the general rules too, as in "You think I'm stupid, do you?" with a rather different meaning than the same sentence with "don't you?" as the tag..
I just avoided all those complications, told them to use "right?" To me, teaching the tags was a waste of time. Things like getting them to use correct tenses in narrative or conditionals were better uses of grammar-teaching time.
To some, this was heresy.