Rain doesn't cause water spots. It is the minerals in the water that causes them. So if there is a lot of dirt on the surface and it rains. Well that is a different thing.
It is another form of protection. It will be more durable than a wax or sealant. Climate does not matter. Climate will play a factor in the flash time of a coating.
Usually little dots like that are overspray when spraying directly onto the panel. Especially if you are outside and a light breeze carries the product to an adjacent panel that has already been wiped.
I have not had any issues with GDS as a drying aid. But have had overspray that appears as a little dots from other products used as a drying aid from other brands.
From an Adams facebook live video, the full coating contains 30% reduced graphene oxide (RGO) and the spray contains 5% RGO. Not sure of the link will work.
https://www.facebook.com/watch/live/?v=952675448476257&ref=watch_permalink
I would recommend to wipe off any product to ensure there is no high spots or uneven appearance. The graphene ceramic will look better and last the longest.
One of things that is a bit disappointing is that Adams does not package the coating in some sort of box. It would stop this from happening. I had their ceramic coating leak on me when I received it.
Didn't this pertain to the actual coating and not the spray coating? I have had the graphene spray coating since 10/2020 and nothing has happened to it. I just place the original top back on it after each use. Seems to be performing quite well.
If I am reading this you applied the graphene ceramic in the spring and want to top it with the graphene spray coating.
See the following thread as it has the answers you are looking for.
I agree with @RayS. Coat them with the graphene ceramic coating if you are going through all the trouble to remove the wheels. Its more work up front but less maintenance in the long term. You can use CS3 to maintain.
https://adamspolishes.com/collections/new-just-in/products/graphene-ceramic-coating™
You will find that you won't need to use a wheel cleaner that often. I ceramic coat my wheels and 95% of the time I use just soap and water. I chemically decon less that a handful of times.
Everyone likes to use a pressure washer. Sheet rinsing with a hose after the final rinse will leave less water to clean up and less spotting. You could try doing that.