Dear Junebug1,
I’ve been facing the exact same problem for a couple of days now. I’m using an IPad Pro 12,9 2018 with Xcloud and I guess that the only latency occurring is because of the bluetooth controller. I tried Dualshock4 wired and wirelessly and the input lag is still present. I bought an Xbox Series controller today to give a try on the IPad which doesn’t recognize it while wired. Same occurs with the Stadia controller which also use USB-C.
It’s really frustrating because when using this xbox series controller on a old Samsung Tablet or on my Google Pixel 3 phone, there’s absolutely no input lag. I wonder if the PS5 controller over USB-C would do the trick ?.. Btw IPad OS 14.7 Public Beta 4 came out today as well as IPad Os 15 for non developper. I’ll download both version and see what happen but I don’t expect much from that.
Regards,