nope. doflamingo himself commented about how little stamina both of them have left multiple times infact in that same chapter.
he obviously got better at g4 as he kept using it. you cant simply say that he didnt have serious stamina issues in dressrosa just because he is fine after 10 minutes at the rooftop. and even on the rooftop he doesnt go g4 after the recovery time.
we have no idea how much time luffy spent regaining his haki when he kept hopping from island to island. they are not the same. luffy got a LOT of leeway in the katakuri fight to heal back up. and its not like he went g4 (the mode that expends so much haki) again right after that. he spent a considerable amount of time fighting in base.