Is StillMind an MBSR course?

No. MBSR is a specific eight-week programme developed by Jon Kabat-Zinn at the University of Massachusetts, taught by certified instructors with weekly group classes and a day-long retreat, and faithful free versions of it exist online. StillMind does not teach MBSR and makes no claim to. What it shares is technique: the body scan comes out of that tradition, and a Techniques course can be built around it. If you want MBSR specifically, look for a certified programme. If you want a shorter course built around your own goal, that is what StillMind builds.