SPR is similar to a minraised and 3bet pot 100BB deep, but ranges are much better defined. I think villain has AA/KK here with a ridiculous frequency, especially in a rush game where he might think he doesn't need to balance by 4betting garbage.

In general when your opponent knows what you are holding and you have defined your hand, you shouldn't continue to put huge amounts of additional money into the pot. On the other hand if it's the top of your range then it's also exploitable to fold it.

I've played a lot of deep PLO lately and I've found out how the nuts (when well defined) isn't usually a very good hand if you are OOP and there's a lot of money behind. In fact it is often so bad that you can't even bet to protect it.