An idea for Puzzle 66~99

I'm kinda lost on how to work with the MARA Pool. Like, if I happen to find Puzzle 66, how do I actually get my payment? I’ve shared my gitHub solo miner that runs on CPU. This is just a thought to prevent getting ripped off. In my mining setup, I pick transactions from the pool using bitcoincore, make a coinbase transaction, and then create my Puzzle 66 just like I do for the coinbase transaction, and throw them in after the coinbase transaction. So, if I don’t end up mining the block, my Puzzle 66 won't be revealed because it’s not in the pool, right? Let me know if I’m off base here.

You're not wrong in a way, but the whole idea wont work. Yes, it wont be relayed to other bitcoin nodes if you set your node not to relay transactions. But puzzle 66~69 will highly likely be solved before you could even mine a single block with a CPU/GPU. I know there's an extremely low chance but it's way way lower than the chance of solving those puzzles with the same hardware. The phrase "same as coinbase transaction" is unclear. You include the transaction that spends puzzle 66 output just like any other transaction that you would include to your block. Your blocks' coinbase transaction is unique and doesn't spend existing utxo.