* For exchanges, you can limit how many withdrawals a user can do per day, such as 3, and show them how many they have left. This will help keep wallets small and fast.
* To see the balances of all zaddrs use `z_getbalances`
* Do not use `z_getbalance` for each zaddr in the wallet, that will be drastically slower
* HUSH has the unique feature of allowing a z2z transcation to spend from any zaddr with enough balance
* This means you do not need to hardcode a zaddr in the "from" part of a z_sendmany and/or move funds around from various zaddrs
* To use this feature, use a single lowercase "z" as the "from" in z_sendmany, such as: `z_sendmany "z" ...`
* When using this, funds will be spent from any zaddr that has enough funds
* Note that a single zaddr must have enough funds to make the transaction, funds from multiple zaddrs cannot be used.
