Honestly, if you carry, carry concealed. Concealed means concealed. If you're doing it right, nobody will know you're carrying concealed, least of all some unshaven barista named 'Topher' who's got sleeve tattoos and shower curtain rings in his ears.
Open carry is for goof-ass twits with something to prove. If your state doesn't allow concealed carry but allows open carry, that's not Starbuck's fault. Change your state laws or make coffee at home. Starbuck's is private property. Respect their wishes and breeze right past their 'NO WEAPONS ALLOWED' sign while carrying concealed. If they spot you carrying and ask you to leave, you need to leave.
There, problem solved.
When the bad guys see you're carrying, they'll just wait until your back is turned, then hit you over the head with a chair and take your gun.
Concealed is always better.
You didn't read the policy, did you. As long as the person carrying does not become disruptive or belligerent, he/she may not be asked to leave.
Is that all that difficult to understand?