I had some MX40 gates. Noisy click when opening/closing which I hate. Call me crazy but ONLY time I have ever blown subs is when using the punch feature. Oh it added punch alright. It was too late and 3 blown drivers later before I caught it. I would never use the punch for live. I sold the MX40's.
Sorry, but I wouldn't blame the gear for your mis-use causing equipment damage. It's pretty much on you, bro. Considering that the punch feature gives a very large boost of the attack it's no surprise that you could be sending a hotter signal than you'd normally want. It's just doing what it's designed to do and if you're blowing things up I'd say this:
You don't have enough rig for the gig.
And I very much disagree with the statement that there is an audible click from the equipment. If you're hearing something there it's more likely bad gain structure.....which would help explain the blown drivers.