I am a developer at a company that operates crypto-currency ATMs, and I passionately want to add Monero to our service. Until recently, there were legal and technical barriers that made this impossible. But those obstacles no longer exist, and I want to get XMR on our machines as soon as possible.
The normal way we (and all other operators) sell cryptocurrency is by sending funds from our hot wallet to a customer's address. This means that we need to be able to send a transaction from our hot wallet every time a customer makes a purchase. This might (and probably will) be much more frequently than once per ten Monero blocks. But if our balance is locked, then transactions will fail.
I know it is possible to lower the waiting period to one block, but I have not seen a way to lower it to zero. Further, that explanation gives the following warning:
One could ask, but why isn't it set to 1 then?
Problem is, the input one-time keys are referenced using an offset. If a re-org would swap the order of transactions, then the transaction referencing any one-time key at the wrong offset would become invalid and would never confirm.
I don't understand fully what this means. Is it possible to manage a Monero wallet carefully enough that a "re-org" never happens? I don't know what a "re-org" is.
You can see that some operators already offer Monero, so it must be possible. The most obvious solution I can think of would be to keep track of transactions and send them in batches, rather than immediately. For several reasons, I would like to avoid delaying transactions if I can. I am also concerned that batching would also run into problems because we still would not have enough unused inputs.