Can you retain a big hatch as second fish or will it be "one over one under" again ?
I'm with you here hoping the reg says 2 fish per day, one of which may be wild. Or two fish per day, only one wild over 67cm.
First option is simple and would work well I think. Worst case is 2 per day only one over 67cm that is frustrating tossing back teenage hatches all day. At least Releasing a big wild you feel like your doing something good but those hatchery fish are put and take. No conservation concern.