If you’re doing an offline proxy transcode for editorial and a relink to camera originals for finish, then the specs you list will be fine. Also, was there a typo? 4GGB of footage is not a lot… That’s about 30 minutes of Canon DSLR (h.264).
I saw your same posting on the Avid community and the answer there is the best you got. There is no way to do that within Media Composer as there are very few things you can do while clips pay without disrupting playback. Adding locator/marks or in-out points are a few of them. If you have a supported mixer you can so a mix during playback.
I’ll have to take a look at this the next time I’m in front of a system with some time to play. Which DNxHR data rate are you using> Are you in proxy mode? Are you importing and to what DMxHR codec? Is it all graphics or just the white text on back? Can you try AMA linking to graphics file and try it again to see if it makes a difference? What version of OS, QuickTime and Media Composer?
Also, you “should” be able to AMA link to the files, then select the clips and your edited sequence and do a “relink to selected” with some trial and error in the relink option dialog box.
Are you trying to batch import into the consolidate clips or the original master clips from the original import? If the former, it will not work. If the latter it should.