I suppose if I was part a group of rogue developers that had access to quantum computers capable of cracking ECDLP based signatures I would go after bitcoins that have supposedly been lost to time or otherwise considered unrecoverable and then use a post quantum-based script to be able to disguise the transaction. I dont know about warning, but time certainly.
That is of course assuming that quantum technology has the capabilities of hacking into someones bitcoins stash, or would these computers only have the capability to attack live transactions currently being broadcasted through the blockchain?

we could get a predyx going of when a CRQC starts a significant attack on a public mempool.

For me, many of these topics seem so complex, and I have such a limited understanding (so far) that I feel like i cant contribute much input yet. Everything that I read on here is vastly different and more complex from the last, so I've been learning a ton.

It has a very simple POS system, does it seem like it has Apple Pay enabled? Surely you don't manually enter debit card info each time. Tap-to pay integration on IOS for direct fiat to sats conversion would go crazy