One thing to note here with these kind of tools, on displayport they typically only allow commands on the active input. Once you switch to another you can't switch back (unless you do it from the other computer). Which is kind of a hassle.

HDMI on the other hand typically allows the ddc-commands even on ports that are not the active input.

Not sure if the above must be the case but it has been the case for all displays I've used.