It turns out that Firmware 2.1.5 (including minor revision 2) has a bug that causes the boost time variable (for DC controller only) to be incorrectly reported as out of range. Specifically, the firmware internally stores the variable as a byte (ranging from 0 to 250), and that times 4 is the actual boost time. When it receives changes from the app, it’s supposed to be dividing that number by 4 for internal storage, but due to the bug it’s not dividing by 4 and consequently the error detection reports it’s out of range. This has already been fixed in firmware 2.1.6 (which will be released tonight or tomorrow). For the moment, the work-around is to change the Boost Time (under Advanced section) to 60 *every time* you make a change to any option. In other words, the actual boost time will be 240ms, but due to the bug, you have to manually divide that by 4 before submitting option changes, to avoid the out of range error.
Sorry about the issue, which we discovered just today.