@mitchop85 While I generally use my Quest Pro with Link, I also still run a Vive Pro1 (amoled screens, Etsy Gear VR lens mod, 2x2.0 base stations, and Index controllers). This is the last Vive headset that was native SteamVR, same as your Index. I also have a high end PC so I think most of these settings should work fine for you.
I use the same non-Meta settings (nvidia, win11, msfs) except I use SteamVR visuals at 100% global manual (not auto) with advanced super sample filtering turned off (or it makes distant objects too blurry), and motion smoothing disabled. Then I set the per app settings for msfs to 350% visuals. Sounds high but SteamVR native reprojection will take care of this nicely. You should also run your Index at 90Hz refresh rate and make sure to set SteamVR as your openXR runtime. This will then automatically throttle down to a nice smooth 45fps. I don’t have the ability to change my VP1 refresh rate (= 90Hz only). In your case, you may even want to try using 80Hz to give you maybe even a bit smoother 40fps and a little more headroom which you may need because while I run a rtx4090, you have a 4070ti (which is still very good).
I suggest you try to follow my recent Meta Q3/QPro thread’s non-Oculus/Meta settings (nvidia, win11, and msfs)in the following thread to avoid me needing to cut and paste all this again. Hope this helps mate and good luck.