My current setup is an arduino r4 wifi and an usb host shield, it works completely well except by an part, the mouse is stuck at 125hz of polling rate, and it is incredible noticeable for me that commonly use it on 1000hz, if i use my leonardo, it works on 1000hz, just in the r4 wifi he works on 125hz. I currently on four weeks trying to solve this
The main problem: the renessas core;
Its not a problem with my code friend, and is because this that i dont provides nothing, is a problem with the the renessas core, and again, you can fell bad for me if you can 
You could move this to Bar Sport and I'll bet a pity party could be organized tout de suite.
Post your host shield model info and the library you are using and maybe someone will have a suggestion as to how you can speed it up.
In order to make all relevant information available to any who are interested in this subject, I'll share a link to the report in the arduino/ArduinoCore-renesas repository's issue tracker:
I solved this on this pull request.