As turns out Swiss and Czechs have already own currency top-up with comparable or with fewer users. So, I strongly believe there are legal issues with HUF top-up and not technical difficulties, since it’s already in Beta since April.
Probably, doesn’t wanna f@ck around with Hungarian bureaucracy, e.g. transaction duty (?) OR they are just blocked by the regulator, because if they can enter why would you use an oligarch’s antique bank’s account for daily banking?! If, this is the case, than we can forget HUF top-up