The reasons some say on here NOT to call before is because we don't want businesses creating rules regarding firearms where there were none before.
If personally, would rather know ahead of time, then be ejected from an establishment. And yes, if a business owner asks you to leave due to the fact you are wearing a firearm, you should leave. It would be wise to advise him of the laws, and also give him a flyer, but it probably won't change much.
Their usual response will be, "It makes my customers nervous." If that's the case, we can just blacklist them and boycott their businesses.
I like the idea of a Riverside Group. Hopefully tonight I will be able to get some research done regarding safe places to meet.