to be fair I run all the controls from simplify3d, and since I removed the usb cable extender, I stopped having connection issues.
The only thing I use the onboard control panel for is running a print from the sd card.
To be fair, it is the only thing you can practically use it for.

If I could flash it, then marlin is the absolute last thing I would use.
It is my only marlin printer and the only one where the firmware isn't worth the silicon it's written into.
In what universe do you make a 3d printer firmware that won't even load filament from the control panel ?

The other 4 firmwares are all excellent, and all different :-)

Right, so remove the caps and let the screws wobble, but keep the couplers.

And yes, I think the extruder assembly can be wobbled by hand.

I'll have to see why.