I have been running tubeless on various tyres for around a year now. So far I have not had any issues.
Today was a strange one though. I was near the end of a pretty long ride and I slammed my rear into a couple of rocks and I heard that demoralising slow hiss.
I had a look and the hole appeared to be very small. Almost like a pinprick size and the sealant was bubbling through. I'll check tomorrow the exact size but it did appear to be small.
What it didn't do is seal the hole. Now like a Muppet I didn't spin the tyre to the 6 o'clock position so that the sealant could pool and maybe help the process along. I only thought of that later on.
Also the sealant is stans and its pretty new, also plenty in the tyre.
Ideas so I can not have another one of these