i have hit the stamina limit in mobius and opera omnia, but that's down to trying to play through a lot of content in one go or playing stages with high stamina costs
though with mobius at least i've got loads of the stamina refilling items from login bonuses and weekly rankings and events (like, over 500) so it's not like that's a major issue and you don't have to use the premium currency
they should follow mobius' example because i think it's the nicest setup i've seen in a mobile game (in-game items to restore stamina/continue if you lose a battle, premium currency dropped in regular battles as well)