Start in Aberdeen, but do not generalise from Aberdeen
Union Street is an Aberdeen city-centre address. Its nearby office, retail and resident catchments should be examined differently from a potential unit in central Edinburgh, a Glasgow neighbourhood or a smaller Highland market. Even within the same city, the direction people travel and the reason they visit a street can matter more than its reputation. No existing-store address is proof of turnover or of another available site.
A serious location comparison involves weekday mornings, lunchtime, evenings and weekend visits. Document public transport access, visibility, competing takeaway offers, delivery arrangements and possible waiting space. For Aberdeen, any second location would also require the master-franchise team to review overlap with the Union Street unit. For Glasgow or Edinburgh, begin with a catchment study, not an assumption that the city is open.