If looking for a new mouse that is NViDIA Reflex-compatible but unsure which ones are?
Here is a list:
Support under wired mode = per-key (dynamic)
Support under wireless mode = database (static)
Link to NVIDIA page: https://www.nvidia.com/en-us/geforce/technologies/reflex/supported-products/
The upcoming ROG Chakram X will be Reflex-compatible.
* Note that you'll need to set the polling rate at 1,000 Hz.