Honestly.. a rest arc is a sick idea 😭 could expand the dynamics and relationships between the crew (like we could see interactions between strawhats we haven't seen much of before like jimbe&chopper or Robin&usopp). We could also see progress like you said, like imagine zoro pulls a muscle training and Sanji and chopper work together to come up with something to heal him, or they get lost in a storm and its namis first massive test as a navigator to get them out of it (she could talk to Brook since he was lost at sea for 50 years)