I'd venture a guess that most any 2005 Caravan still on the road is a failed wheel bearing or missed oil change away from being junkyard fodder.
I understand wanting to defend the moral high ground but it's ok to be realistic. Write down the pin you choose on the vehicle in a conspicuous place (door jamb by the data plate is my fave because it's where I normally look to get the vin back in the days I could just call in a PIN). Notify the customer and explain the potential issues. Do the thing, get the money, get on with your day.
All of us keyboard badasses on here would do the job better, faster, and charge more. I myself have raised the issue and challenged the status quo when the ability to change the PIN first arrived in our collective toolbox and a few people had the audacity to mention they'd set some PIN's to 0000 because eff the customer, they're always gonna have to use a locksmith now!
I'm older and less interested in causing a ruckus over the way other people choose to fix things. I still replace stripped screws when I find them and pick up trash off the sidewalk (provided there's a receptacle to drop it into), but I'm not above farting in an elevator either. On a moral alignment chart, I'm probably somewhere between chaotic good and chaotic neutral.
The original question was asked and answered as was the followup questions.
It is our job to get the customer back on the road as quickly as possible. Nothing illegal or unethical was suggested (IMHO). The customer had a problem, the problem was solved...they're driving again. Job well done and no one was "screwed".
One would hope that, after losing a key and going through the expense of getting a new key, they would be sure to keep at least 2 keys from that moment on.
Well you do you, but I feel that is giving the customer a disservice. Next time they go to a dealer, or have a locksmith that cannot EEPROM and need a key you're essentially screwing them.
I put things back to OEM spec, unless there something 100% preventing it from happening.