A nice improvement (and a need for us) would be multi-currency support.
We have many customers who want to pay cash in their own currency.
We are also facing people (mainly tourists) who spend their last local bank notes and pay the remaining in their own currency (a single purchase with multiple currencies).
Matt from Shopify here, hope you're having a great week so far! I've submitted this as a feature request on your behalf to our POS dev team. :) If/when it becomes available, you'll be notified directly!
In other words, don't hold your breath. Issues have been piling up for a year and Shopify POS development team is completely AWOL. Shopify helpdesk acts more like a gatekeeper.