I'm dealing with some concepts I've not 100% wrapped my head around, so I'm throwing this out to the guys here to see how plausible it is.
A master clip contains all meta data associated with the clip. Batch importing of a quicktime or other video file will keep this metadata and use it rather than that of the source file.
So my thought is this. Somehow generate an ALE containing all relevant metadata from the source files. Import this into Avid to make the offline master clips. Batch import the DNxHD transcodes of the original RED files to the appropriate master clip. If everything goes the way I'm thinking, you'll have your HD downconverts as well as all the source timecodes and information without manually changing any information in Avid (like most of the hypothetical workflows I've been seeing).
The only part I'm unsure of is making the ALEs. The rest should work. I've tried the batch importing using the log tool to make clips with time code I made up, then batch importing an irrelevant QT file to that clip. As long as the duration matched, there were no problems. If the duration was too long or too short, the video was sped up or slowed down to match. If the meta data is coming from the right clips, this won't be an issue anyway.
It's obviously not as good as importing the Red RAWs right in, but we work with what we're given. Let me know what you think.