I don't think it will be a issue for the short period of time
If I have a can of Alum Coating (Karnack 298) that is 95% full sitting on the roof - for let's say 2 weeks, any issues with the solvent gassing out. Granted there is a gasket on the lid and it's nice and tight.
I currently just left it on the roof, and plan to use it in about 2 weeks time.
Yay or nay ?