I don’t know of anyone. What’s it going to cost to add 32 cc to the engine , with the rebore, Nickosil plating, and parts ? If the price goes past $1000 you can probably buy a decent 900 motor and gained 150cc and 6th gear.
I have not done the 90mm kit but have done a number of 90.5mm kits for race bikes. The biggest reason to do it is to fit a certain race class. As mentioned selling your bike and buying a kawasaki supercharged bike (busa,rsv4...etc) can be cheaper and maybe wiser.
That said we are talking motorcycles on a Ducati forum so making more than 200rwhp is not something you are likely lookiing for. If you are simply trying to freshen a 750 or make 900 power without swapping motors you may get close with the kit. No a built 750 will not make the power of a built 900 and likewise a 900 will not make the power of a built 1000. I see no reason the kit would not add 10-15% rwhp reliably which should get you close to a stock engined 900.
That said if you drop in a 800 motor you might gain other upgrades as well such as a slipper clutch and 6 speed. The 900 also gains you a dry clutch if you want one. So what you have left out is why you would want to big bore a 750?
Some of us like to build those bikes that not everyone else wants, sometimes to be different and some times to answer a question in ourr heads. I see no reason to NOT big bore a 750 as long as you know what you are getting and why you want one.