.........
Since there was no history of this type of failure with previous models, surely a simple cure would be to revert to the OM-D 5 MkII design?
That would add considerably to cost. A friend of mine was kind enough to take some pictures of his EM5.2 especially for this thread, with the base plate removed.

EM5.2 with the base plate removed. The front half-cover is magnesium. Whereas the rear half-cover with the speckled paint appears to be plastic, so my friend says. He concludes this because it feels warmer to touch, and the screws into it have a coarser thread than those into the metal front half-cover. Also he notes the liberal amount of thread lock compound added to the screws into the front magnesium half-cover.

The tripod socket is integrated into the front magnesium half-cover. A rigid, heavy duty anchor. And now we also understand why on the EM5.3, the tripod socket is located so much forward - its so because the rear half-cover is plastic and as such not suitable for a heavy duty tripod socket!

The base plate seems to be a metal stamping. It only weighs 6 gram, so it is probably aluminium. Those areas around the screw holes are not washers, but just unpainted areas.

Unlike the EM5.3, the EM5.2 base plate does not contain any weather sealing material. And the battery chamber lid remains captive on the body. One could say, this base plate is more decorative, rather than adding much to the structural rigidity. The volume between this base plate and the camera is not weather sealed at all, the weather sealing is rather done between the front and rear housing and the battery compartment instead.
[ATTACH alt="This is the "battery compartment retainer", a metal stamping that apparently looks like mirror chromed, so it is most likely stainless steel. It is a loose fit sandwitched between the base plate and bottom cover with two screws passing through it. There are also two "studs" in the camera body, on both sides of the hinge and besides the screws, to hold this retainer in position during assembly."]2520910[/ATTACH]
This is the "battery compartment retainer", a metal stamping that apparently looks like mirror chromed, so it is most likely stainless steel. It is a loose fit sandwitched between the base plate and bottom cover with two screws passing through it. There are also two "studs" in the camera body, on both sides of the hinge and besides the screws, to hold this retainer in position during assembly.
[ATTACH alt="Here on the left my EM5.2 with the base plate attached (the right is my Pen-F, disregard it). Notice the four little "feet" at each corner. These do two things. Once, they prevent the paint of the bottom plate being scratched (say by sand grains) when putting the camera on a table. But these are also the four contact points when using an optional L-plate, preventing rocking. The bottom plate is not flat but ribbed and has screws etc that would cause rocking, if these 4 "feet" were not there."]2520912[/ATTACH]
Here on the left my EM5.2 with the base plate attached (the right is my Pen-F, disregard it). Notice the four little "feet" at each corner. These do two things. Once, they prevent the paint of the bottom plate being scratched (say by sand grains) when putting the camera on a table. But these are also the four contact points when using an optional L-plate, preventing rocking. The bottom plate is not flat but ribbed and has screws etc that would cause rocking, if these 4 "feet" were not there.

Here again the EM5.3 plastic base plate for comparison, with the several weather seal strips.

Here again the EM5.3 camera base for comparison. The tripod socket is attached to the plastic front half cover.

As a pictorial analogy, looking at the two cameras as tools, the EM5.3 is built like a precious jewel hammer, the EM5.2 like a heavy duty mallet. Note that I am not insinuating one is any better than the other - it is a matter on how each is used. Nobody will hang the mallet around his neck to go to the opera, just like nobody should use his silver pendant hammer to drive a nail. Also note this is not metal vs plastic, it's about cheaper vs more expensive housing design. It just so happens that one CAN design much cheaper using cheap plastic types. If one WANTED to, one COULD design very solid and very light camera housings with plastic, but it would then definitely cost more than metal, much more! Olympus has been making losses for many many consecutive years - they cannot afford expensive high tech plastic designs, they have no other choice than use cheaper plastics/designs to improve their profitability. Fortunately they still make very well built heavy duty cameras, for those that are prepared to pay what it costs to make them.