I do not think you'll have any problems at all. TO be safe, you could call them, but would have to wait until Monday. The talk about the 24-hours is that you must protect the surface from things like foot traffic or anything that could damage it while it is still fully curing, and you must keep the room temp within specs for that 24-hours as well so it can cure. Once the stuff has changed color, you could tile it, but if flood testing, you have to wait at least 12-hours, and that is dependent on the room temperature staying within the stated min/max along with the humidity levels. Longer is probably better before flood testing just to be sure. One reason why I like sheet membranes...as long as it doesn't freeze while the thinset is curing, you're good to go after the initial cure for your flood testing and tile laying.
Because the stuff remains slightly tacky, it is easy to get it dirty - dust and stuff will settle and stick. Unless it's really bad such that it could create a bond-breaker, it should be okay. Again, this is one reason why companies have tech support lines.