Project Manager Errors - Copy instead of trim "Unable to match audio channels"

I've run into a fairly large hiccup using Project Manager and I'm hoping someone might suggest a potential solution.

I have a large number of broadcast spots that are cut using a variety of sources, including many "Broadcast Masters" consisting of 6 audio channels. When I try and trim \ consolidate the project using project manager, it always copies the media files which don't match the preset (so all the 6 channel masters) and states, "Transcode error: Unable to match audio channels".

I understand why it is copying the files instead of trimming them (6 channels not matching the 2 channels stated in the preset selected), but unfortunately these promos are short and copying an entire 50+GB media file makes for a massive "trimmed" project. Is there a way to have it transcode the media files using the audio config present in the original files ? Or any other method of trimming down the project which gets around it copying the entire episode?

Thanks for your help! @