same situation for me, I HATE micro-USB connectors used for power.. Anyway, I got it done couple of weeks ago, after advice from the team..
..with the board oriented with 5x USB connectors side UP...
- 5v POSITIVE goes to JP1 (right behind OTG USB connector) either pads, round or square, as the pads are connected together..
- 5v NEGATIVE to the LiPo-BATT connector pads (top LH corner, near SW-PWR switch) pin 2, round, NOT pin 1 SQUARE! Pin 2 is also connected to the board ground, you can check that for continuity, zero ohms, with the SMAs bodies and RF shield.
For the time being, it works well for me with just two square pins soldered in place, later I'll put a "proper" dc connector somewhere on the board.