I could be way off base, but my unit has no play between the keyboard and the tablet, and even though it doesn't latch, it closes firmly. I wonder if the cheapest ones weren't ready for prime time, so to speak.
_________________________
pa4X 76 ,SX900, Audya 76,Yamaha S970 , vArranger, Hammond SK1, Ketron SD40, Centerpoint Space Station, Bose compact