Hi, I'm sorry but I have not seen your post, its so many in a day that its easy to miss it.
Let me try and help.
So, you have a 1440p monitor right? Using RSR to get 4K its not gonna cut. Your monitor does not support that resolution.
Now, if you mean VSR then its different. But thats a feature that ive not tried that much.
My advice?
I would stay with 1440p if you are happy with it. I know that 6900XT is meant for 4K but i normally prefer a high fps experience over resolution.
But If you really want and have a great sum of gold burning a hole in your wallet. You can go for a 4K high refresh rate monitor and then use RSR to increase fps.
Good luck
The Englishman