PLEASE explain to me why this makes ANY sense
- Spending undefined witness (or Tapleaf) versions (ie, not Witness v0/BIP 141 nor Taproot/BIP 341) is invalid.
- Witness stacks with a Taproot annex are invalid.
- Taproot control blocks larger than 257 bytes (a merkle tree with 128 script leaves) are invalid.
- Tapscripts including OP_SUCCESS* opcodes anywhere (even unexecuted) are invalid.
- Tapscripts executing the OP_IF or OP_NOTIF instruction (regardless of result) are invalid.
#bip444