No entry stamp in passport
 

So far as I can gather, to fill in the form hotels need to know the date and port of entry: they always try to read the entry stamp. So I would certainly get this straightened out before leaving Beijing.

“. . . got the feeling they ended up using my wife’s info."

Not sure I understand. I can understand how an official might just forget the stamp, but did they put your passport through the scanner? Did you give fingerprints? If for some difficult-to-accept reason you are not in the system, then I think you're going to have a very long day.

My suggestion would be to find a Chinese speaker, at the front desk if no place else, who can call Airport immigration and ask how you should proceed and -- very importantly -- what documents you should bring, like your boarding pass and hotel registration.

My most recent entry stamp is 2 years old because I don't get stamps anymore. This has never been a problem when staying at hotels.

But you don't travel in China with an L visa, do you?

Touché; I don't.

Even if you no longer get stamps you should be printing out the little slips with your date of entry on it after you go through the automated machines. It eases the checking into hotel process immeasurably.

I have a stamp from ~5 months ago (I encountered a checkpoint without eChannel), which I show to hotels, if they ask, but most of the hotels I stay in know me quite well, and don't care.

This may vary locally. I just checked into a hotel and all they wanted was a quick shot of the photo page of my passport on their mobile; didn't even look for the visa.

Sounds a bit dodgy. If this was the only place you're registering at on this trip I would be worried.

Not the first time it's happened.

And as I've mentioned before, when you stay in a hotel it's the hotel's responsibility to register. You're responsible when you don't stay in a hotel. And booking online gives you proof where you stayed if there were a question.

(I remember a notice at one hotel a couple of years ago from the local PSB: If a hotel doesn't register you properly, contact us and we'll pay you a reward.)

I'm sure legally you'd be OK. But it could result in significant delays at the border should they raise a fuss. I have heard of a recent case where the traveller was delayed by two hours due to a missing registration from a hotel on a trip two years ago. They were sure that they had registered at the hotel but apparently it wasn't in the border force's system.

Well, I've been travelling in China for many decades and know a potential problem when I see one. And I don't see one here. (If they hadn't taken my passport photo, which has rarely happened, that might be a different story.)

Why didn't he ask the border control person to simply call the hotel?