Hi Rob, I hope I have put this in the right Forum.
I got my EM1 M3 the day of the announcement from Olympus and JIP. When I got the camera there was a bonus of the Anker Powercore+ unit. The unit just arrived and it has 3 usb3 outlets and no usb3 out. The unit will charge the battery. but not power the camera.
I tried to order the one on your link but as I live in Australia. Anker will not supply this to Australia just the version I got from Olympus Australia.
I ordered from Amazon Australia a RAVpower PD Pioneer 20000mAh 60W 2-Ports Power Bank. and a RAVpower 60W charger. I am glad to tell you that this combination WILL power the camera from the power bank and the charger. This gives the users a second option to power the camera.
Regards
Wayne