Nesting Pens for resource production feels ok, but the free cross breeding feels OP. Without pens you'd have to consume seeds, so my idea is to extend that concept to the pens. For every cross breed attempt, consume some number of seeds.

By "enabling" Chicken Feeder to supply seeds to the pens this would also add some depth to the mod & give this block additional value.

• My concept is that seeds would reduce the amount of time. If there are no seeds, cross breeding will only happen every 40 minutes, and every 60 seconds the Pen would check for an available seed. If the pen gets to consume a seed, the cross-breed timer is reduced by 35% (netting roughly the same 7 minute breed timing for the cost of 6 seeds).
• Config options for upper limit, seed consumption interval, and seed consumption reduction would let folks tweak the values. E.g. check every 30 seconds, and reduce by 20% each time for
• Bonus would be cross breeding config per chicken. This would allow higher tier chickens required more seeds to cross breed.

Its not a bad idea. I was eventually going to add a hud to the nesting pen for more control to go to the player. finding a decent to balance is a goal of mine. Even though I added support for chickens mod. I orginally inteded this to be a mechanic for just vanilla chickens. I have a lot planned to add more options and making chickens more useful in general. If chickens mod got updated than cross breeding will be more work as it no longer gives you hire stat chickens only breeding same chickens. But I'm not sure if they updatedto curse or not.