RE: https://mastodon.social/@hrbrmstr/117529813223970582

Confirmed PAN-OS is disabled by default:

https://docs.paloaltonetworks.com/ngfw/help/12-2/device/device-setup-session/tcp-settings

Also confirmed that it is disabled by default on F5 BIG-IP:

https://my.f5.com/manage/s/article/K50411377#MPTCP