Thanks for your reply.
It has been a while since I looked at Braidpool. What they mean by shares in their documentation is subtly different than what I am exploring in this thread (and in a more economic-focused fashion over in this thread.
From Braidpool’s readme:
Custody of accumulated coinbase rewards and fees is performed by a large multi-sig among miners who have recently mined blocks using the FROST Schnorr signature algorithm. Consensus rules on the network ensure that only a payout properly paying all miners can be signed and no individual miner or small group of colluding miners can steal the rewards.
I have not yet fully been able to grasp how they intend to have the above claim be true. So one of the focuses of my reserach is to not introduce such a signing aspect and instead use game theory and random share selection to keep it entirely non-custodial.