@Scott - “tightening” the build platform latch screw is actually kinda tricky - on some platforms you have to remove the aluminium plate to get at the screw, on others where you can access the latch screw from on top, you have to screw it down until it releases the latch, then screw it down some more, then screw it back up into the latch.
The main thing is - can you get any rocking motion at all when the build platform is latched on to the Z-axis column bracket? Even the slightest motion at all? It should be completely rock solid, and as one piece with the Z-column, so that rocking it only rocks the whole machine. There should also some resistance/force needed to push the latch completely closed.
I’ll try and make a video about adjusting the latch and post it in a new thread, phone is busy making a timelapse at the moment…