To my understanding, there is unfortunately only one way to improve the motion blur on the pimax 4k: the timing of the shutters.
Pimax uses a high persistant (slow switching, aka cheap ) 4k display together with high speed shutter glasses to blank the eyes so that we do not see the persistance while switching to the new frame.
Somehow some of the 4k use a slightly off-timing so that the shutter switches on (you can not see the frame diplayed on the screen below it) to early and/or off (you can see the frame on the screen below) to early. This results in smear and/or ghosting.
There is no easy way in improving the switching time of the display unfortunately (my assumtion, because that would render the shutters useless). Maybe a smal increase of switching time would be possible via increasing the voltage of the lcd driving circuit (like most of the overdrive features work on gaming-lcds) but it seems that with the 4k diplay it is either not possible (cheap driver circuit) or already done within the manufacturing-tolerances and still not fast enough. Maybe someone could hardware-mod an overdrive (higher voltage) some way, but i think such a mod is just a not reasonable effort to do.
So we are left with a control of the timing of the shutters. And for some reason pimax is unable or do not want us to alter the timing by adding a timing-slider in piplay. A pitty.
My 4k had so terrible ghosting that i removed the shutters. For slow paced games it works fine and shows the potential of the 4k screen, but for racing or fast paced shooters i simply can not recommend to do so.
Wait for the 8k it has much faster swithing lcds (low persistance) or hope that pimax offers a panel upgrade to all the 4k users which they said to look into but i doubt it will be released.
Much more feasable business wise is to release an upgraded version of the 4k with the new displays of the 8k after 8k release. I am pretty certain that will happen this year already.