In a single-signer Taproot address, the BIP86 tweak has a clear meaning: the output commits to no script tree, only a key path.
But in a two-party MuSig2 channel, I think it does something extra. Without the tweak, Alice could in principle embed a hidden script path into the funding output — one that lets her spend unilaterally. If both sides independently apply the BIP86 tweak and verify the resulting output key matches, it is effectively a mutual confirmation: “nothing is hidden in this output.”
So my question: in a MuSig2 channel context, is this the intended security guarantee of BIP86 — preventing the counterparty from embedding a hidden script path? Or does the channel protocol have separate mechanisms that already cover this?
