Tutors: professional artists or industrial design students?

I would focus on learning from either design students, or from resources you can find online. There are a lot of sites/instagram folks/facebook groups focused on design sketching.

Design sketching is fundamentally different from anything taught to classic art students - because it’s about rapid communication beyond just rendering form.

With that said, once you understand the difference, I’m sure traditional art classes could help you develop your understanding of form/light and shading beyond that point. I know for myself, art was a standard part of our pre-college curriculum so coming into ID with a foundational background is also important.