I believe the mathematical break even point on dead wild fish goes something like this.

A mark select fishery only makes sense whenever the mark rate exceeds the release mortality rate. If it's not at least that high, it's pointless to go mark select.

The excessive sorting actually results in MORE dead wilds... take for example ocean coho.

The main difference between mark select and "kill the first two" is the total number of encounters required to get the job done.... and whether the wild fish end up in the bottom of the box or on the bottom as crab bait.