Well I had heaps of milk and was still feeling really full after a feed on one side only. When I started block feeding the LC said to just use the same side for as many feeds in a row as needed to actually empty the breast. At first that took me over 24 hours of feeding from one side only and in hindsight I think that was a bit extreme and caused some imbalance in supply after that.

Sounds like you're managing to empty a side in one feed though, so maybe just do two feeds from one side in a row and see how that goes.