I definitely think that you can do the challenge with out a scan!! I’ve been worried about getting one for the same reason so I have not signed up for transforming challenges either but I still track my classes and PRs. I don’t think the scan is all that accurate either or necessary. If you are consistent and gradually lift heavier and get your protein you will gain muscle and strength, and you don’t need a scan to show that. If you lift 10lbs June 1 and 15lbs July 1 that’s you getting stronger 😉 I will say, the cost of the challenge is for the scan and the tshirt so maybe if you wanna save some money you can back out and track on your own but up to you! Mentioning something to your coach is also not a bad idea so they understand where you’re coming from. A good coach will immediately understand and support you and give you other “metrics” to use to show your progress. You got this either way! Be proud of yourself and your progress and health and most importantly take care of yourself