One interesting use case that came up in later experiments:
In a recent IK + CSFS run on Bitcoin Inquisition:
I realized that OP_INTERNALKEY implicitly assumes that the internal key is trusted.
In practice, this trust comes from the control block verification — reconstructing the Taproot commitment chain and ensuring that P → Q holds for the given UTXO.
From this perspective, reconstruction is not just a debugging aid,
but a prerequisite for reasoning about identity-bound authorization.