Particle relative time material node doesn't work with beams

The particle relative time node outputs 0 for the lifetime of the beam. Is this a bug? Any hopes of getting this fixed, or is it going to be ignored like most Cascade issues since Niagara is in development? Thanks!

I think its a limitation, Dynamic parameters dont always seem to properly work either.
as can be read here: Unreal Engine Issues and Bug Tracker (UE-13679)

and since Niagara is on the horizon only really game/cook breaking bugs will probably addressed.