We do advertise fast dry times. We do cover dry times in a pre-service email sent to customers. We base the stated dry times from our average customer's service situation.
I'd say at best only 1/20 people ask about them and make it known it's an important issue for them.
It's a simple response - you are seeking a company to clean your carpets, not seeking who can apply moisture/water and get the fastest dry time possibly detrimental to quality of clean. Your goal should be to find the company that can clean the best with safe dry times.
If they need more we will cite the variables, will you need pretreatment, will you need rotary steam cleaning, is your carpet a low pile, is it a very thick pile, are we cleaning 250 sq ft in a 5000 sq ft home, or 4500 sq ft in a 5000 ft home, etc.
The fast dry time or your house will implode from mold scare tactic has run it's course in my market imo. Mostly they seek a solid service without being sold "soap" to double the price upon entry.