I’m in the process of drafting a paper on resolving the problems associated with Haag’s theorem: Haag, R. (1955). “On quantum field theories,” Matematisk-fysiske Meddelelser, 29, 12.
This involves resurrecting direct-action theories as a possible account of how Nature really works. It is perhaps not well known that John Wheeler himself was attempting to resurrect the direct action approach in 2003, together with his colleague Daniel Wesley (“Towards an Action-at-a distance concept of spacetime”, in A. Ashtekar et al, (2003) Revisiting the Foundations of Relativistic Physics, Kluwer, 421-436). In this piece, Wheeler and Wesley not only speak favorably of the Wheeler-Feynman theory of electrodynamics but recommend applying the same basic approach to quantum gravity. So perhaps, reports of the alleged demise of direct action theories have been premature. Comments welcome, especially if you have a concern that you think should be addressed in such a paper.