I dont know if this has been talked about in other posts, apologies if it has.
Ive just worked with the C300 for the first time, a multi-cam shoot shooting long interviews.
According to my post guys all the files came back as 5:15min clips. I'll talk to them tomorrow and get more info as to how they transcoded, but its not easy on the sound synching if this is all they have to go by.
An old post, but in case you're still looking for an answer: I believe the length of the shots is fixed (max file size in FAT32 maybe?). Syncing should be easy though; because all the files are the same length you only need to sync the first files, the rest you can place directly behind your first synced shots.
Hope this helps!