IMHO you and your sa made the right choice on the mosaic face. I would have selected the same. Why select options that can be purchased from store or h.com. Not saying eventually our choices won't be available. That's always possible.
BTW, if you had other strap options that you were considering during your order, your sa can see if strap(s) available to order separately. I've done that a few times. Sometimes it also has to be a special order (it’s same price as regular leather/exotic straps) and some not. Here's some of my extra bands I have for my and DH SO watches. Hardware separate cost but love how I can within a couple seconds switch out my bands to go with my bags or clothing.
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