This is not a new problem. I have identified this a little while back and already made the correction to my home made printer, Printalicious..



It is not necessary to mount the z probe on the opposite side of the rails. It just needs to be inboard of the nozzle. Just to make sure that if things do go sideways the whole time things are going sideways if the print head is coming down, so is the sensor. And so long as the sensor is inboard of the nozzle should the nozzle bottom out on the bed the z probe will be driven down at a faster rate than the print head. It will become a see saw in the right direction.