When I mentioned different regions, I just meant the currencies that would be most logical in those regions. No geo-locating needed.
It wouldn't bother me at all if certain currencies got more business than others due to lower fees. This happens when a store puts items on sale; they usually sell more sale items than non-sale items. It's just smart business: You make money from a higher volume of business or you use the sale for a period of time to attract more customers who hopefully find other things they like and don't mind paying a bit more after a while.
If the lower fee thing really works, we'll find out by trying it, either across the board or in these limited "sales". If the lower fee doesn't attract added business, then we'll be confident that we could go forward with a system that's built for more profitability.
Instead, at the moment, we've split the difference on the fees, so we won't learn anything.