When I worked with hardkernel years ago, they didn't care that I was uninstalling petitboot or that armbian recommended removing it. Linux isn't even supported on many x86 systems people are using for OMV.
On your system. tobetter could not reproduce on his system. And yes, I know others have seen it.
OMV and armbian work very well on all of the odroid boards I have (many - xu4, hc2, hc4, c1, c2, c4, etc). And after four years, no other odroid board is using petitboot. No other manufacturer is using it either. Armbian supporting hardkernel boards makes hardkernel money by selling more boards. They are not going to tell you to not use Armbian.
10 mins??? The system is in use. I would have to figure out how to put petit boot back on it, take the system apart to attach a serial connection and then try to replicate. Follow that by trying to figure out why it is happening. This could be hours and hours. Easy for you to offer my time to do that.