Glad you found the story useful. In case you missed it, there is a follow up to that original posting …
https://crescendomusicloft.com/2024/01/21/update-to-my-journey-through-music-performance-anxiety/
The second posting deals with the strategies I actually tried when preparing for a subsequent public performance and the results I experienced.

Delighted that you found the blog posting a little useful. There are actually two postings there, one (I think the one above you read) that goes through some of what I read when I first started to learn about MPA, the second posting describes several things I tried when preparing for another performance. I never did try a video recording, although as you pointed out that would be higher up the ladder than audio recordings because the people we send a video recording to would actually SEE us!!! And that would ramp up the anxiety – which of course is the point of the exercise anyway. I did use audio recordings as you have done and that does simulate a performance, even if in a much safer way than actually sitting down in front of an audience and playing for them. So it is a great way to start up the ladder. You can even change the anxiety you feel with sending an audio file of yourself playing by carefully selecting who you send to. Sending to a family member is lower on the ladder. Sending my recordings to my teacher was also safer because my teacher hears me play every lesson. But when I send him a recording knowing that the purpose of the recording was to simulate a performance, that makes me more nervous than sending simple lesson exercises. And sending to a friend really gets you up the ladder because I think friends are more likely to listen critically than family or teachers. So, you can do different things just with audio recordings to vary the level of anxiety. Of course, there are lots of exposure therapy activities you can do much higher up the ladder to get used to anxiety before a full blown public performance. Once I started playing a weekly “concert” at home for my wife, that really helped me get used to performance anxiety. Come to think of it, she can be even more scary than a room full of strangers!