I’ve experimented with this quite a bit and while there is a noticeable difference the higher you go, I’ve found this to greatly diminish over 300mbps. I’m currently running 400 mbps as well and have zero audio cutouts here while minimizing compression artifacts. I’m also running close to @Kjaye767 settings. I think I’m at 2800 per eye using OXRTK override.
I haven’t fiddled much with 72hz though admittedly. I will try that out over the next day or two.