The comments so far are a good start, thanks.
We're having rain or spring temps so have been on red klister & haven't had a chance to test purple brews.
I can report on some experience. I too have found Toko green spray works well. In the relatively short tests I've done (<15k) it holds up as well as iron on. I agree you can produce a nice thin binder layer w/ the spray & spreading w/ your thumb before it dries. Far easier & faster than tube or stick binder.
I also got the Swix klister binder spray. The applicator is different & maybe better. The Toko is made to be used w/ a vertical ski & spray can. The Swix can is held upside down w/ a horizontal ski. It was easier to get a really thin layer w/ the Swix.
I've also tried the Swix Red & Toko Silver spray klisters. Both tended to ice a bit in loose wet snow (temp. 33.5F) & didn't kick all that well. Both are non-fluro. But I didn't have a groomed track to test them in either - trail had only been groomed for skating. The Swix Red applicator is a ~50mm wide fiber pad w/ an aerosol release you press to the base of the ski like shoe polish. It was very easy to apply far too much kister. And it seems likely rubbing w/ the fiber pad will mix the Red spray klister w/ whatever is already on the ski base. None of the other Swix sprays I've seen use this applicator. The Toko spray worked much better.
I was told by a wax tech that overspray is a problem in windy conditions. He tapes the glide zones or uses cardboard w/ a slot in it. A coach I know said they had found the warm spray on klisters wear off in a couple K if applied over a hard wax. A binder is essential it appears.
Instructions for most of these say they should be used at "room temperatures" & I don't know what happens when applied at really cold temps. Also don't know how many applications you can get from a bottle. Any of you have experience to report?
Still hoping someone out there has tried using a hard wax spray over a klister to prevent icing???