6. Preview zone control. When drag left a conrol edge to min-width then it begins to move the whole preview zone.
It not an issue and could be perceived as a positive feature or a negative feature.
[+] control of left and right zones could be started by touching anywhere to the left or right of available space, respectively
[-] left or right edge control should not (in my opinion) act like moving zone. For this user should touch the center (or somewhere between left and right control zones).
You should rather add pinch-to-zoom feature on preview widget as Dreamy Griffin (https://contest.dev/chart-android/entry50
Umi Super, Android.