DAMAGING THE TRIPOD MOUNT
The tripod fitting is a metal plate attached by four screws to a polycarbonate mold as shown below. Applying too much stress to this fitting can cause the threads to strip or break. All four of the thread shafts are broken off in the below photo. In hindsight attaching straps connected by a cable tie to additionally secure the housing to the tray as a means of relieving the stress on the tripod mount is explained further down in this section.
Many underwater camera trays accommodate a variety of housing brands and sizes. The housing is attached to the tray via the housing's tripod mount (arrow #1 below). Note the WP-DC34 housing feet do not touch the tray (arrow #2) even with the tripod mount flush with the tray. The two "feet" on the bottom rear of the housing are against the rear raised lip of the tray (arrow #3) to prevent the housing from turning. Also note the back door of the housing does not rest on or against the tray (arrow #4). If the feet rested on the bottom of the tray tray or the door rested against the tray lip it may put pressure on the door causing it to shift resulting in a leak or a total flood.
The downside of the above mounting scenario is all the pressure is put on the tripod mount when holding the camera housing in your right hand instead of the tray handle with a housing/tray/arm/strobe combination like the one below that is not neutrally buoyant. Under some buoyancy situations it is not always possible to hold the tray by the left side handle and push the shutter button with the right hand. These type tripod mounts are not intended to bear that kind of stress.
My solution to alleviate the stress on the tripod mount is to additionally fasten the housing to the tray with two nylon hand straps from two pet leashes (with the chains removed) and one cable tie. As shown in the photos below the straps are inserted through the top neck strap loops on each side of the housing. The leashes are then pulled down across the front of the housing and joined together with a cable tie underneath the tray. I cut the cable tie off and discard it at the end of a dive day. I purchased a bag of cable ties. It is not possible to open the housing door while mounted to this tray.
The MOST IMPORTANT part of this method, or any other, is to be certain the pressure is equally placed on the tripod plate. To check this (after securing the straps to the tray) loosen the tripod screw and check that the housing does not lean forward or backwards as that will put pressure on either the two front or the two rear tripod plate mounting screws.

 

No doubt there are more creative methods of reinforcing the tripod mount. I would be cautious of placing any objects under the housing. They may create upward pressure causing a portion of the housing to flex which in turn may cause a leak or flood. This is even more of a concern if those objects were under the door portion