well, problem is - redshift doesn't render x-particles (OVDBmesher or Trail) in picture viewer (and Redshift Render View), only in IPR. Using of Cache object doesn't help too. Oh yes, Standard and Physical render work fine (i mean sees the mesh). Just have no idea.
A while ago now but just in case... It does with the demo here, OpenVDB of either particles or trails with/without a simple material and with just particles or trails (no mesher) with or without material with a Redshift Object tag (set appropriately)