I don't see how it could be set higher at this point. But I wouldn't set it as high as you are proposing if it could be set higher. I'd say 1mm higher at the max. But I would be afraid of the ring getting messed up. You can ask IDJ if it is even possible, though, and how much would it cost.
I am told they would just add metal to the prongs and then set the diamond higher, and it wouldn't be noticeable. So it is possible, but I am a little nervous to have that kind of work done...
Do you think it would look best somewhere between where it is currently set, and where I am proposing? Or is it better to leave well enough alone?
I personally think it looks perfect just the way it is. That setting lends itself to a 'swoopy' look and I think it is beautiful!
The culet is visible as it should be. If you set it higher, you are going to have a blank space under the diamond in the setting. I think that would look peculiar - almost like the setting doesn't fit the stone.
Is Vatche going to do the work? I think that you deserve to be completely happy with your ring and while I think it looks fine now, I also think it would be fine raising the diamond very slightly so that there is a small gap at the bottom. You have to love it and not settle. If the height is bothering you now, it probably won't get better over time, at least in my experience.
I have the same setting without the pave and a smaller stone so it sits a bit higher (pic in the link below). I think for your stone size it's set perfectly though.
I think it looks perfect. I know some people like the stone set high to clear the culet or make the stone look bigger. But your ring has very nice proportions and I would leave it just as is.
Your ring is beautiful and the diamond looks huge on your finger! My concerns for changing the height of the diamond would be the same as what others have mentioned. I would also be concerned about the diamond knocking into or catching on things when it is set higher. Yours seems to be set at a perfect height for the diamond size and setting style.
Some questions to consider: Have you been wearing the ring for a while and had enough time to determine if you will be forever unhappy with it the way it is? Is the current height something you can learn to live with/get used to?
Whether or not you should reset higher depends on your tastes. I would not. I prefer low-set rings both because I find them more aesthetically pleasing (less of the "wearing a doorknob" look) and because I bang them on stuff less often. But if you prefer it to be set higher... well, you are the one wearing the ring and looking at it all the time.
Your ring needs to be pleasing to YOU. I know this is bugging you. For me, I much prefer the way yours is set over these others you posted.
You can see the bottom tip of your culet which is important to me, but these others settings I think look less pleasing because there is too much open space. They look like the stones are set too high. Just my opinion.
I think it's fine as-is, but if it's bugging you, work with the vendor/maker to find a solution. Messing with prongs can really wreck a ring, though, so I'd caution you to have insurance and an alternative. Honestly, getting a new setting might be better.
And one nitpicky pet peeve of mine from your diagram: it's culet (pronounced cue-let), not cutlet like a piece of meat.