I wouldn't do it, but I am not familiar with that process.
C2 has fail-safes built in and is programmed to support many systems.
You have to take into consideration what systems will be using it.
Browsers in Fullscreen usually take up the whole screen, taking away some toolbars.
If you change the resolution it may make browser toolbars come back.
It may mess with browser in some other unknown way, because the browser was already expecting a set resolution.
My point is this should be tested in a small way until you know more about it.
If I were going to attempt that, I would do that in only 1 part of the game.
This part of the game will stand out to the players.
They will naturally give you good feed back if it is liked or bad feedback if it has errors or is disliked.
Maybe do it once the level is finished or in pit stops or something.
You don't want to do it in a very important part of the game if you are just testing it out. It may upset some people or make the game unplayable to some as a result.