What kind of evidence? If I do a test in HK, do I just need a photo of me grinning and holding a test up or do I need a video showing me, my nose and the test developing in some independent cinema style?

Yes. One or two time-stamped photos are a good idea. Nobody at immigration will ask for this because fingerprinting requires the majority of their time. The thing is, if you happen to catch Covid less than 90 days from entry, it's conceivable that you would be requested for proof of your test.

Bring an antigen test kit on your carryon. Do a test and take a picture of the result. Do not overthink about it. Perhaps, nobody will check your result but you have evidence if asked to provide it.

This is actually inconceivable to me.

Me too, but apparently it can still happen that you're asked for it.
I now suggest to bring a new, virgin test along. If there's some idiot that asks for the actual test along the way, just whip out the test and do it right then and there.

To get into trouble, 4 rare stars would need to line up against you:
1. You catch Covid in China
2. You spread it to other people
3 The hospital is connected with the government
4, The government dislikes you

Based on my understanding, only point 2 is an actual law, and you would need to be a moron to violate it, That being said, we're only talking about $5 to eliminate all of these risks. Well, point 4 isn't in your control...remember Perry (he is still alive,,,just not in China)

E Channel opening on the 15th of May! Same qualifications for use as before. Great news!

WOWOW!
Remind me again how to apply? I've forgotten...

Anyone taken the HK/mainland train recently and can speak about the test requirements? Is it the same as other crossings where self administered RAT is sufficient?
I'm coming from the US to HK for a weekend and want to go to Shenzhen for lunch (already have train tickets booked and have a Chinese visa) so want to make sure I don't need to get a PCR.

You don't need a PCR

The MTR site has current requirements (a rapid test within 48 hours in your particular case).

https://tnews.highspeed.mtr.com.hk/en/d/

I just returned from the Pudong place to get a new RP.

A few things have changed since the last time I did the drill:
-the in-person visit seems to be even more mandatory than it was previously
-the first step is to take a picture in their photo booth that looks just like the subway station photo booths, but apparently the photos it generates are connected to your master file
-then, you need to go to a separate machine with your photo ID number and passport
-this machine prints out your application
-then, you need to go to a window to sign your application and show your face, which gets photographed again
-my agent was waiting at window 16 for me and ~5 other applicants
-I'm not sure what his value added is for renewals now that the process is more automated, BUT he was able to get me in front of the agent at window 16 in less than 10 minutes; others were not so fortunate. Furthermore, he contacted my company and my landlord to get documents from them. Yes, I could have done this myself, but if I missed a step, I could have been rejected
-every staff member I talked with there was quite friendly

In summary, neither the application that I prepared in advance nor my subway station photos were used at all and they didn't seem to care about my work permit (the plastic card) either.

Did you utilize the services of the famous Vincent to get this renewal done?

I used his company again, but Ronald did most of the heavy lifting this time around. He would need to raise his prices (I actually didn't ask him what his fee is this year; I will find out when my passport is ready) a lot to get me to switch horses because he has all of my old documents (e.g. translated diplomas, medical records, criminal background check) on file. I'm sure he would happily give me all materials if I asked him, but it's much nicer not having to think about them. And again, the idea of going all the way to Pudong (as you know, the location of the visa place is about as inconvenient as they come) and being told that you forgot a silly document is not appealing to anyone, let alone those of us who wait to the last possible day!

How long is the RP valid for?