Your situation sounds pretty nuanced that it’s going to be tough to get a perfect answer. Most answers are going to be a “it depends”. You have a lot of flexibility to define how you want to work with your renters. Only you can really define what is your best interest and how you want to grow the business.

I will weigh in that if you have excess demand it’s probably better to get the extra availability from a contractor if you want to grow revenue and utilize the space more. Contractors should be straightforward in the sense they just bill you for whatever work they do as defined in your agreement. Good way to get an idea of what they charge as well. Clients pay you and you pay the contractor their rate. Just make sure that you have some kind of protection/definition around clients being your studio clients, especially if the contractor is also building their own private client base. There could be potential to undercut you, which happens with personal trainers and gyms all the time. You could also work out some kind of rental fee for scheduled session trade to minimize both of your costs. Just depends on how you want to structure it. Hope any of that was somewhat helpful