“To set a custom number in the box, you have to click the up or down arrow to increment or decrement the values (you have to be patient on this one in order to get the desired value and please also take note that it will not accept any odd number values).”
This is a VERY bad UI design. Please ask the programmers to change that.
Also, I held the spinner down for a long time, but eventually, it reached a maximum value, and the values stopped moving.
E.g. currently I can set the spinner value to 2560 x 1440.
But, it is not possible to set the spinner value to 1440 x 2560
This means I can’t use the SpaceDesk.
And attempting to rotate to portrait mode in the Primary PC didn’t work either.