[mu53]

Do you have a link to any of these studies? It sounds interesting, but I couldn't find anything with my searches

[sneak]

No, they're usually not published. I encourage you to do it yourself.

Looks like Instagram at least does do TLS cert pinning, but it looks like there are patched binaries that disable it.

https://github.com/Eltion/Instagram-SSL-Pinning-Bypass