On our Facebook DJI forum someone came up on this idea:

Osmo Pocket power bank extension

All you need is: Power bank FeiyuTech Handle Charger + DJI or other Accessory Mount.
I think it's a good idea even though the Pocket gets bigger.
The best idea could be power bank with USB-C connector on the top that you could put directly to the Osmo as extension rod

Links:
FeiyuTech Handle Charger

Gimbal Holder Mount Accessories

Multifunctional Expanding Switch Module Connection

Hello and good day kotwPL. Thank you for sharing this information with us and thank you for your support.

It wasn't long. Someone has start to sell power bank extension on Aliexpress

STARTRC DJI OSMO Pocket Portable power bank Type C USB Charger for DJI

kotwPL Posted at 1-19 01:23
It wasn't long. Someone has start to sell power bank extension on Aliexpress

STARTRC DJI OSMO Pocket Portable power bank Type C USB Charger for DJI

Looks really cool! Thanks fr sharing!