The PCE working group is responsible for the Path Communication Element Communication Protocol (PCEP). PCEP allows a Path Computation Client (PCC - for example, a head-end router) to request paths from, or have paths created by, a Path Computation Server (PCE).
The WG is actively working on adding to PCEP the concept of an "association group" which binds together arbitrary sets of LSPs and/or policies for the purposes of path computation. The base draft for this [1] is very flexible and allows for many follow-on innovations, ranging from associations reflecting common policies to those mandating resource diversity and other relationships such as bidirectionality and resource sharing. Another significant piece of work in progress is the extension that allows a PCE to act as a central controller, by instantiating path state on each hop in an LSP [2] and using a flow specifier to add traffic classification to the head-end node of the LSP [3].
There have been some new proposals to clarify RFC 8231 as well as refinement to stateful PCE extensions for state synchronisation between stateful PCEs [4] and relaxing constraints [5].
[Last Updated: August 08, 2019.]
[1] https://datatracker.ietf.org/doc/draft-ietf-pce-association-group/
[2] https://datatracker.ietf.org/doc/draft-ietf-pce-pcep-extension-for-pce-controller/
[3] https://datatracker.ietf.org/doc/draft-ietf-pce-pcep-flowspec/
[4] https://datatracker.ietf.org/doc/draft-litkowski-pce-state-sync/
[5] https://datatracker.ietf.org/doc/draft-dhody-pce-stateful-pce-optional/