I have a client that logged and captured 80 hrs of footage for a documentary on Final Cut Pro and wants me to cut it on Avid. Will Metacheater work to create an ALE so I can batch import the quicktimes into Avid with the metadata intact?

If FCP puts a timecode track into the QT then metacheater will be able to read it and make an ALE. I'm not sure whether FCP does that on capture though. Prob best to test with one and see, metacheater works on PC and Mac.

Your problems are more likely to start with the codecs used rather than the metadata.  What codec are they using to export the QT files?  For example, ProRes codecs are not available in the PC world.  See if you can get them to install Avid codecs LE and export in one of the DNxHD codecs.