So my two questions are A), do you think that lack of felt down on the bottom of the rail could have anything to do with the failing glass panes? or will an overly tight glass pane channel cause a cracked glass?
Fwiw, F*rd Transits had an ongoing problem where the front felt would slide out the glass guide channel allowing the glass to contact the metal directly,IF the door glass was half way down or more,closing the door could and did cause even a tempered glass to shatter.
So by my reckoning it could potentially cause the issues you've had.
A tight glass,especially if laminated could/would crack due to flex caused by the forces imposed by the regulator,they can generate considerable torque due to the gearing.
I've witnessed inner door skins flexing by sticking/binding glass while trying to operate the regulator regardless if it's manual or electric.
I have to agree with Carls last statement too.
