So, what you're saying is that if I want full body tracking, I should just get a Vive?
Forget anything major like that for at least another 10 years or longer.
You paid too much for a prebuilt machine as an upgrade.
And on a side note: Your 1080ti doesn't provide 90 FPS in VR Chat?! What kind of card do you need to get 90 FPS in vrchat? Until recently, your 1080ti was the top of the line card out on the market.