Ultraseal prevented my back tyre deflating at about 80 on the motorway.....covered the back end in blue goo, which worried me initially and brought the puncture to my attention, but only lost 1-2 psi.
Your tyre fitter won't thank you for it !
Personally, if I've got a puncture, I'd rather be aware of it & get it fixed properly.
A decent puncture outfit helps.
And if I'm stuck, then Carole Nash Recovery is my friend
I was at a presentation last week by Bridgestone , the same question was asked . The reply was never use it as it invalidates any tyre warranty as it is not recommended by ANY of the tyre manufacturers .