> In particular, you care more about privacy when you are contesting a
> close of a channel or other script path because then the miners could be more
> likely to extract a rent from you as "ransom" for properly closing your channel
> (or in other words, in a contested close the value of the closing transaction is
> larger than usual).
Not sure this point holds, independently of which Taproot/MASTmechanism deployed,
any time-sensitive transaction will likely leak its "contestness" by the setting of its
nSequence/nLocktime fields. E.g, for LN, justice tx are not encumbered by a CSV
delay which distinguish them from a non-revoked spend. And when you're relaying
htlcs and need to close unilaterally channel to prevent different settlement on
incoming/outgoing links the HTLC-timeout tx broadcast have a nLocktime set.
Beyond LN, timelocks are a privacy leak and miner-withholding vector for any
offchain protocols but this problem is not tied to Taproot design. Confidential
enforcement of them would be great but that's another debate..
Antoine