Derk, how do you intend to set up your cabin? Will you use the mass for a sleeping platform, couch or grow bed? Where do you have space to add mass and still allow movement?
In other words, only you can really decide what and how to build build in your particular situation. If you check out the Alternative Energy forum
https://permies.com/forums/f-10/alternative-energy you will find several threads that talk about
RMH. They are full of drawings, videos and testimonials about what has worked and what hasn't done so well for them. I'd suggest you grab your favorite beverage and plan on a session at the computer. Some of those threads go as long as 10 pages, and the response count is 40 per page. It will be worth it!