I'm archiving using archive.today as well for a few days now.
It's archiving JSON + threads on there as well as on the regular wayback machine.
Today I figured that creating another archive after an archive already got created doesn't properly work right now for archive.today, but I figured out the changes that are needed to fix this already.
It seems archive.today only does this when a correct referer is given, the user agent needs to be a web browser + there has to be a submitId.
I'm already looking for new posts, that's possible by using the catalog.json timestamps.
When I detect that, I'm creating another archive.
For the MP4 archiving I will have to look through the breads of course, but that's not that complicated either. I already prepared structures for that job, but I want to fix archive.today first.