Dual will have twice the amp limit if in parallel. And last twice as long if in series.
two 30 amp 2600 mAh 18650 in parallel will have a 60 amp limit. and 5200 mAh in series with a 30 amp limit.
id love to have a 26650 dna30/40 mod with a 26650 battery that has an insane battery life and relatively low amp limit (to get the high mah). plus the size could still be very small
I am not very familiar with the 26650 batteries , is that their claim to fame , superior mAh over the 18650's? I assume they can be much more powerful as well.