Cycle time matters not a jot when you have one of these.

[Oliver1655]

The reason you can't start from the outside is the round expands with each level of splitting. If you were to start with the outside then when it did the next inner level it would cause the splits to bind against the outer splitting wedge.

 

[KiwiBro]

The reason you can't start from the outside is the round expands with each level of splitting. If you were to start with the outside then when it did the next inner level it would cause the splits to bind against the outer splitting wedge.

Which is why I made a point of mentioning progressively positioning the wedges. Sure, there'd need be some concentric overlap between the ringed wedges and this will produce bind, but with enough setback between each wedge ring, perhaps the bind will be fleeting and not much of a 'player'?
The difficulty with this is where is the ram pushing, and at what point would the wood in the wedges/knives break free from the round before being fully split, as the round progresses further. Sure, the next round will finish the splitting (or perhaps more accurately, slicing) of the previous split but also leave more trash that is no good to anyone.

I'm currently exploring a rather different way of quickly creating firewood. Not sure if it will work, but worth a shot.