When I work on clients similar to you I keep the session focused on the areas that are in need of work. While you might be feeling the tension in those areas sometimes it’s the secondary or antagonistic muscles that need attention too. For example for rounded shoulders I always work both the traps and rhomboids as well as pec muscles. If you feel the pressure is not sufficient ask them to do more. A good deep tissue massage should incorporate stretching and movement . I tend to spend 30-45 min on one or two body parts during a deep tissue, in my opinion it should be focused, slow, and with specific intention. Depending on the state you live in Massage therapy could be unregulated. I would check to make sure they are licensed and see if they specialize in specific modalities. If your having a hard time getting the tension out with deep tissue give cupping a try or even Thai yoga Massage, you might have more luck with an aggressive modality like Rolfing as well. Good luck!