IR is starting waaay too long when some forest pack objects are present - it takes about 5-10min (sometimes longer) to start compared to some 10-30sec. for a regular render, maybe that's not IR's fault at all but instead some forestpack's pre render scene optimizations just going mad, not knowing what some sort of Ir is enabled, and Ir just follows constantly restarting, reparsing but still starting at some point. Or at least that is so in my case, at first I even thought it just crashed, frustrated I went to smoke, came back just to see it hasn't and Ir renders fine. Testing again proved it to be repeatable, and while starting IR, the closer camera is to FP objects (some free, converted, laubwerk trees in my case) the worse it gets so probably that's some of FP's optimizations getting in the way.
EDIT:
tried IR with some regular FP's preset grasses and stones - no such delay, it seems that problem lies in FP+Laubwerk's trees+IR as those trees are not just some meshes but some sort of procedural geometry which in turn does some pre render optimizations
EDIT 2: 100% sure it was those trees cause if imported via laubwerks library browser, converted to mesh and then scattered by Forest Pack, same one where those original ones were used(so same settings same amount) there is no issues with starting IR at all so anyone interested just be aware of that.
Maybe it's a common knowledge (those trees need to be converted) which I wasn't aware of, for somehow I never used laubwerk trees a single time before today...
