I had a Vortex on it, that I took off the R6, but now have a Driven 1/4 turn. The Vortex is a screw on type, a bunch of turns. Crappy pic with the Vortex, then the Amazon pic of the driven. You push down a little over the blue area, 1/4 turn counter-clockwise, pull it off. I thought I had a pic of it on the bike, I don't right now. Comes in a variety of colors. Three screws hold them on.
I do like the Driven, quick and easy to use. Nice and easy at the track or elsewhere, no key required and it doesn't wear you out trying to remove it. LOL I have them on other bikes too, that is why I went with it for the R7, there are similar alternatives though. The R6 came with the Vortex, that is how I got that one.
There are several that can fit and are now being produced for the R7 specifically. STG has put out a YouTube video for installing the Driven Racing Halo cap -
A word of caution if you do go with any aftermarket keyless/twist off cap - be mindful of where you are parking your bike for longer periods of time. All it takes is one asshole to walk off with your cap - or dropping whatever object, or substance they might decide to into your fuel tank.
I desperately want to get rid of the silver cap since I think it sticks out badly, and I don't just want to try to cover it with stickers. I've even tried to get quotes from anodizing companies, but none of them in my area take on smaller jobs/less than a bulk order and are backed up. Please post an update with a picture if you end up finding/installing anything!