Why not just use the filename as source when conforming in DaVinci? Each file will be its own source. Works fine for me. If you look at the TAPE column or the SOURCE FILE column what do you see? If I remember correctly, the REEL is added to the ALE file which you need to import first then merge the files into that in order to see that value in the TAPE column.
If you export an AAF or EDL to DaVinci, it will use the value in the SOURCE FILE as its source and expects all files to start with 00:00:00:00. So if you AMA directly and export AAF/EDL, and in DaVinci set up to use the filename as source in the settings, then it will conform and you can color correct from there.
I redid 40 hours of transcoding to DNxHD (Was MXF ProRes) from the AMA H.264 files specifically to be able to go to After Effects and DaVinci... now I'm discovering that AMA from the H.264 was the way to go in the first place... (sigh).
Forgive me for the novice question (very new to AVID) how do I take a sequence full of MXF DNxHD clips and conform it to the original H.264 files?
If the clips were transcoded to DNxHD 145 or higher you can just use those for final color correction as you won't gain much if anything by going back to the original H.264. Export AAF or EDL to DaVinci and point to the Avid Media Files folder as the source in the Media Pool.
Timeline conform options in "settings", check the used embedded sources checkbox for "assist using" and try again. That should be the correct one for conforming to MXF files. But beforehand, add the Avid MediaFile folders to the media pool.