I believe I have found the location of one of the secret chest no one else has found yet. I took my friend here after our raid group dipped and we've been exploring since. So many times we thought we found the chest because of lights, but alas we've been tricked. Sly Bungie :-) I'll keep updating if this ever catches fire. If anyone has already been there, I'm sorry for being late :-(
-
If there is a third chest, I think it is in the platforming section and requires you to do something to unlock it. One theory I have is that all three players must touch all the platforms in order. I can never find three players willing to take that time though haha.