I have one question.
Does ZCash allow HD Wallets for Shielded transactions? If so, how the in the locking script can be HASH160(pubkey) where the pubkey is from unlocking scripts, as the spender who creates the unlocking script can create any public key?
I can assume that the CHECKSIG works fine as it checks with signature and pubkey which are created by the same person (spender). So irrespective of whether HD Wallet is used or not, it should work fine.