The problem is that X-Plane 11 doesn't have a global weather model, just a local weather bubble. Tools like ASXP just update this local bubble all the time. So X-Plane has no clue what weather you have 200NM away from your current position, so aircrafts can't pull that info from X-Plane. I think this is supposed to change in XP12.
Until then, the only option for aircrafts is to pull that data from external sources like real-world Internet-accessible sources, ASXP or... (and that would be my preference) from the SimBrief OFP which contains wind data for every fix in the FPL. So, if the user downloaded a FPL from SimBrief, CL650 already parses the OFP XML anyway, so it has the wind data readily at the fingertips, to use on a subsequent WIND REQ.
By taking the SimBrief-supplied wind data, this would match most closely an actual pilot entering the per-fix wind data from the OFP, just done automatically, which then matches the planned performance and thus fuel data.