Patek Philippe

My friend will be working in Riyadh soon (for a 2-3 year contract) and is very interested in visiting the Riyadh Patek AD (perhaps multiple ADs?) to pursue a steel Nautilus.  He fully understands the extreme scarcity, waiting game, patience required, consistent visits and friendly, open communication.  He knows 2 or 3 years may not be nearly long enough to expect a Nautilus but he will still try.  

However he's unaware of the local sensibilities when conducting a visit to the AD. Also he's aware of the male dress expectations in general when in public (no shorts, preferably long sleeve, sneakers) however would it be to his advantage to dress slightly better when visiting the AD boutiques?  Such as dressier trousers, dress shoes and long sleeve dress shirt?