Mouse cursor on multiple screens with different PPI

I'm using a 4K display along with a Full HD display with both almost the same physical size and it brings some mouse cursor problems to me working with it on the default Windows settings.

As the mouse movement speed depends on the pixels, it's very slow on the 4K display and very fast on the Full HD display. Is there a windows setting or application to move the mouse depending on the visible distance and not the pixels?

Another problem is the virtual wall between the screens I can't move the cursor from the upper half of the 4K screen to the Full HD screen:

Windows creen settings

How is it possible to virtually stretch the cursor transition area of the Full HD screen to the one of the 4K monitor?

The smallest problem, nevertheless painful, is the cursor size which varies between the screens. Is there a way to keep the same visual mouse size on both screens?

Solution 1:

Virtual wall

LittleBigMouse fixes the virtual wall problem in its current version, as Flexo013 pointed out in his answer
DisplayFusion provides an option for skipping the Virtual wall in it's paid Pro version - thanks to Ƭᴇcʜιᴇ007 for the link
There is a study published by Microsoft in 2004: Mouse ether: accelerating the acquisition of targets across multi-monitor displays. It finds that mouse ether improved participants’ performance on a target acquisition task across two screens running at different resolutions by up to 28%. Unfortunately, the mentioned application Mouse Ether isn't available for download.

Cursor speed

It appears that Microsoft has finally fixed the mouse speed issue in Windows 10 Insider Preview build 16273 so most probably the fix will be in Fall Creators Update (2017). It is activated by changing the scaling of a screen.

There were three projects which address the cursor speed problem on multiple screens with different resolutions.

DpiGonzales on github which works very well on my system - thanks to Sandor Drieënhuizen for developping the tool and for sharing the link
There is a project called LittleBigMouse on github, which is in alpha state and not stable on my system.
The most configurable program I've found is Custom Screen Speed on its developers website, but the configuration has to be set manually and it is not stored. Therefore it has to be reconfigured at each system start.

Cursor Size

No projects found yet

Solution 2:

Found this solution, which should at least fix the virtual wall problem, on a different thread, originally from Steve:

Perhaps LittleBigMouse could help you out? It's an alpha application, but it seems to be focusing on the issue you're having.

Github: https://github.com/mgth/LittleBigMouse

Download (Releases): https://github.com/mgth/LittleBigMouse/releases

I have been using it myself with a 4K UHD monitor and a 1080p Full HD monitor and this does exactly what you want.

As for the cursor speed, this can be solved by changing the scaling of the screen within Windows. For example set your 4K display to 200% and your 1080p screen to 100%. Then the cursor size and speed should be the same on both screens.