My 3D printed part just arrived to me. I hope it can protect Lipo pack if drone will have small problems with the landing or ... during small acctidents. The part fit perfectly my Zippy Compact package and I can mount or remove it very quckly.
I paid for printing this element 4$ and camparing it to battery cost it not so bad.
Scope of phase is closed, there won't be any additional changes this year. Now I need to focus on failsafe options and then tests.