Can confirm this is still an issue in 4.26.
I think the development team should take note that there is an assumed paradigm of windowed applications generally respecting the combination of mouse DPI raw input AND windows pointer speed, and as a result, allowing a seemless transition between interacting with multiple different applications (such as sketchup, blender, illustrator, unreal). Unreal Editor seems to be one of, if not the only, application not respecting this established UI paradigm.
And we’re not talking about engine runtime, which understandably SHOULD just use the raw mouse input, like the runtime of any other game would, as well. We’re talking about windows control type interactions, window resizing, numerical scaling when you drag the mouse, panning your blueprint around in the editor window, etc, things you would expect to behave the same way they have for the last 20+ years of window based application usage.
It is quite common for users to want to use a higher DPI setting on their mouse, for the sake of finer granularity control in full screen applications like games, and then reduce windows pointer speed to offset that and still have reasonable speed at windowed application level. The way Unreal Editor is currently set up removes that possibility and forces the user to either use a much lower mouse DPI, or precariously navigate the various interactions in the editor at high speed.
This does not seem like an optimal situation.