How do I adjust a door that runs on threshold

Hi folks.

I'm a handyman in the Toronto area. I have a project to adjust an aluminum hollow commercial door from grinding on the threshold.

The door and frame is black and as temperature rises, it doesnt take much sun to cause expansion to make the door rub the threshold.

I've added a several shims to the bottom hinge, which had helped but not enough on the hot sunny says we have had recently.

The brand is commdoor. I'm advised by a tech advisr there that I can use the Robertson set screw at the top to correct sagging . Apparently it will add tension to the glass. I dont understand how this works but more importantly I'm concerned that putting tension on the glass even through a plastic shield will break it and then we have a bigger problem.
Any advise for me?
Also the threshold has been secured as it was moving. Apparently the threshold can be removed and replaced as it is held by screws on the ends. Any point in replacing it, if it is now secure?

Hoping someone is watching this forum can assist.

A late reply to this but, commdoor is an Aluminum Door manufacturer that we deal with from time to time. Still in the "Division 8" realm, but outside of the scope of most distributors who supply Hollow Metal and Wood doors. Likely why you didn't receive a reply. You can reach them direct here: Commdoor Aluminum