Not all 200's are created equal, and a Dunlop 200, Michelin, Pirelli, etc...will not all be the same size (even if the aspect ratio is the same). Each brand has their own unique profile (Ever compare a Dunlop 120/70/17 to a Pirelli 120/70/17 and look at the sidewall difference?).
A 200 will not automatically be 5mm wider on each side over a 190. You can't even begin to assume that without taking the aspect ratio of the 190 into account, along with rim diameter.
I've used plenty of take off 200's on my past R6 and ZX6's. Don't take everything you read online as gospel, some people talk in theory, and some people actually have first hand experience. I'm not saying it will work for sure, without knowing if you have a tire hugger/specific chain length, etc, but more than likely, it'll work just fine for your use.
Yep! All of this. Having settled on Pirelli years ago, I've since then got their spec sheet almost every year which has the actual dimensions of their tires. It's amazing how big their 180/60 tires are. Here's some examples, for Pirelli race tires:
180/55: 184 width, 641 diameter
180/60: 190 width, 656 diameter
200/55: 195 width, 656 diameter
200/60: 200 width, 662 diameter
This reminds me I need to get the 2019 spec sheets. They came out with some tires this year that are not on my 2018 sheet.