For phantom power applications, I think I'll try to devise a way to simultaneously:
1. Operate the DR-100 from inside the included soft case by cutting out flaps and/or open rectangles and circles for desired plug-ins and key/wheel access, and
2. Locate and utilize a small enough battery pack with 5v/2A xxxxmAh output that will fit in the case behind the unit and power it externally.
Now, powering 10mA mics @ 48V, the external + internal li-ion combo should all work perfectly and untouched for upwards of 6 hours, assuming that there would be a smooth automatic transition from ext->int power, although I'm sure if you had to yank the pack's adapter plug out @ low charge LED you could do so without negative impact.
In the end I hope we're looking very viable handheld/pocket operation here!