Hi,
As you mentioned, the built in gesture and touch in Enhanced Input are mainly for mobile.
It looks like Windows/Mac touchpads are treated as mouse events.
As a workaround, you could enable Mouse for touch in the project settings, but it would just be like using a normal mouse.
If you would like, I could escalate this to Epic as a feature request.
Please let me know!
Some extra information, the editor does have some implementations for Mac trackpads as shown here: https://dev.epicgames.com/documentation/en-us/unreal-engine/viewport-controls-in-unreal-engine#usingmagicmouseandmagictrackpad
but it seems lacking for track/touchpads on Windows according to this post: https://forums.unrealengine.com/t/request-support-for-touchpad-tap-with-two-fingers-to-right-click/2463907.
Regards