I hope my suggestion may help or enchance the gaming experience.
I think DS should increase the Stamina bonus (I.e: 60 Stamina) per time to 600 Stamina. The reason is when player reaches Level 151, the “Expert” section will be available, but the cost of Stamina is 20 and not 7 per fight, that means there is just 3 fights and the 60 Stamina is gone and have to wait another bonus, even 3 times bonus per day for 60 each Stamina can only take 9 fights and not each fight cannot obtain what you need.
I am not quite sure what the others players feeling and I hope DS can notice this pain point and makes it changed in the near future.
Thank you for your attention!