I worked for safelite as a mobile pro for about 2 years. Just for reference, mobile pro's are in areas where there is no factory support to come help you if you mess up, so you get it right the first time.
The urethane, depending on temp and bead size, will cure in 24 - 48 hours fully at 70 degrees. If it is exceptionally cold out, you had VERY low working time, and it would cure a bit faster. If it is hot (like the 100+ heatwave the east just had) give it a full week.
Certain vehicles like modern japanese cars have a MUCH smaller bead, so they cure faster. Old chevy vans, like the savannah, and certain large SUV's that most of the SPL guys have tend to have a thicker bead, so they would need more time.
We did not use stops, nor tape to hold the windshield in place (the tape was for the molding to cure into the urethane). Once the windshield is in the urethane, and you press it down, it VERY rarely slides. Only on the GMC/Chevy vans with those giant windshields did some of the techs need a stop on the passenger side to help solo set the windshield.
One thing you guys should be aware of, is that OEM glass tends to be better than SGC (safelite corp) glass. SGC glass sometimes has variable thickness, and doesn't always fit as well, or has waves. If you can afford it, or have the insurance for it, always get OEM glass.