>
> some wallets (e.g., Andreas Schildbach's wallet) don't even allow it - you
> can only spend confirmed UTXOs. I can't tell you how aggravating it is to
> have to tell a friend, "Oh, oops, I can't pay you yet. I have to wait for
> the last transaction I did to confirm first." All the more aggravating
> because I know, if I have multiple UTXOs in my wallet, I can make multiple
> spends within the same block.
>

Andreas' wallet hasn't done that for years. Are you repeating this from
some very old memory or do you actually see this issue in reality?

The only time you're forced to wait for confirmations is when you have an
unconfirmed inbound transaction, and thus the sender is unknown.