I've got a business trip in May to Eastern Europe and have a 4 hour daytime layover in Frankfurt on my return trip. Sinn's HQ is according to Google Maps about a 15 minute cab ride. Would a four-hour layover be enough time to visit the factory store, make a purchase, get the VAT refund paper processed and go through departure immigration?
I will already have a boarding pass, carry-on luggage only and am flying business class but want to be through security and at the gate 60 minutes before departure. I've flown through Frankfurt before and am not worried about navigating the airport but am curious about the additional time required for the VAT refund and departure immigration. Is this doable?