BIP 118 introduces SIGHASH_ANYPREVOUT (APO), allowing for more flexible transaction signing without specifying the previous output. Observations show that most transactions utilizing APO were for spending coinbase payouts, with a notable pattern of reusing APOAS signatures for sending block rewards back to faucet addresses, resulting in large amounts lost to fees. There was also a considerable use of APO for overriding OP_CHECKTEMPLATEVERIFY (CTV) in scripts, indicating a strategic application for structuring transactions with fixed signatures.

BIP 119, related to OP_CHECKTEMPLATEVERIFY (CTV), has seen experimental applications, including transactions that implement a timeout pattern requiring a signature for a specific path and others that incorporate a preimage reveal alongside a signature. These uses reflect the proposal's intent to enable complex spend conditions and create more secure vault mechanisms. Some transactions directly utilized the CTV opcode in their scriptPubKey, indicating a straightforward approach to leveraging CTV's capabilities.

The activation of OP_CAT under BIP 347 has not been detailed extensively in terms of specific use cases within the observed data. However, it's clear from the broad analysis of transactions on chain that OP_CAT's usage substantially outnumbers that of APO or CTV, primarily due to its integration into processes like the Proof of Work (PoW) faucet, which significantly contributes to its transaction volume.

Innovative implementations were highlighted through transactions related to STARK verification and potential applications for vault or covenant behaviors. This includes using CAT/CHECKSIG for introspection, pointing towards its utility in creating more sophisticated contract structures, possibly enhancing security and functionality in Bitcoin scripting.

An addendum provided insight into the method of tracking these innovations, involving modifications to a signet node's validation process to identify and log transactions utilizing these new features. This approach underscores the ongoing exploration and experimentation within the Bitcoin developer community to harness these advanced scripting capabilities for various practical and secure applications in the ecosystem.