Difference between 19-21 OTK tag chassis

Are there many changes to the OTK tag chassis between the years of 2019-2021?

When the '19s came out, everyone said “you need a '19 to be competitive”, but once the novelty of a new kart wore off, I think most people preferred the '18s or the '20-'21s.

They all are good karts for sure and can win at any level, but from what I heard, the '19s feel like they have a little bit less front grip. I don’t know what the exact structural changes were between the years, but it could be a tick more or less caster or something like that.

I felt like the 20 was a little more twitchy and had a bit more front grip than the 21. I had the seat in a little different spot between the 2 karts though, so that’s a factor also. With the 21 it almost feels like there’s a little less caster at standard settings, although on paper I don’t think that’s supposed to be true.