The draft minutes from https://codimd.ietf.org/notes-ietf-108-tsvarea say
"Colin: There’s a long history of this, to Brian and Jana’s points. One outcome of SPUD and PLUS was that we believed we didn’t know how to solve this well, and we started the Path Aware Networking Research Group. We looked at what didn’t work before. Please look at that, and engage there." At the risk of immodesty, I'd suggest starting with https://datatracker.ietf.org/doc/draft-irtf-panrg-what-not-to-do/, which talks specifically about obstacles to deployment for "Path-Awareness", including end systems not trusting networks and networks not trusting end systems. (I'm the editor, but it IS a research group draft) Best, Spencer
