I have the same question. If you upgrade to the latest version 26.2, you will find that the coalescing of mouse movement events has become more restrictive—they are downsampled to match the screen refresh rate. This has become similar to how the system handles touch events. Unfortunately, regarding this change, I haven’t been able to find any interface provided by Apple that allows access to the original data points before coalescing. It seems that on macOS, the only way for an application to obtain relatively precise and raw mouse movement events is to set isMouseCoalescingEnabled to false. I hope someone can help confirm whether this understanding is correct.