we made some good progress and pushed out version 2.5, (actually it has been shipping for a few weeks)
The main change is that we only use Alnico magnets now and instead of magnetizing those fully in either direction go from full magnetization to completely demagnetize.
The advantage is a reduced air gab and shorter magnetic path length resulting in improved holding force.
It was a little tricky to find the ‘0’ point, or just how much of an external magnetic field needs to be applied to demagnetized the magnets but not more. Eventually we found a solution, magnetize them in alternative directions repeatedly while decreasing the amplitude of the field. This all happens in less than 1 second.