I find those quick release clamps, straps and similar devices the scariest things in the world when it comes to attaching cameras. Sure, the lock is rated for 200lbs, but for how much is the tripod mount on the bottom of the camera rated and under what conditions? I think I'd much rather just have a pouch into which you drop the camera when not needed, which also gives the camera/lens some environmental protection. There are lots of mini-backpacks/ouches available that are easy to put on and take off and give quick/easy access to your gear.
My minimum would be an E-M1 and 14-35mm f2 lens. I would rather have that on the camera strap over my shoulder, with the camera effectively resting behind my back, than bumping on my chest. But when pushing through scrub and the like, I'd rather have everything packed away and hands etc free to negotiate obstacles. If you happen to slip or whatever, then a camera on your chest isn't the best place for it to reside. But since the OP doesn't provide details of the likely conditions etc, we have no real idea of the potential risks involved and what else needs to be carried on his treks.