There is much more than "two commonly deployed used" of MPTCP, to name a few : OpenMPTCPRouter is an improved fork from OVH Overthebox project ( https://www.ovhtelecom.fr/overthebox/ ), Tessares is a company that provide key in hand MPTCP solutions for many ISPs ( https://www.tessares.net/customers ). MPTCP was designed to be transparent for the end user, so you might be using it without knowing it, from your phone, your computer or your internet box