A fat Li-on battery like the Ving 850 would make sense.
That is one thing I like about the Godox flashes. (V850/V860) For the price, the battery life, and full amount of features (except the old style lock wheel :-( ), I think this should be the next build model for flashes. Options? Manual vs TTL and built in radio or not. I think Canon could sell a decent amount of manual only flashes with HSS and rear curtain sync.