I thought I'd leave this in here in case anyone ran into a similar problem. Earlier this year I bought a used R5. It was low shutter count and virtually unused. I could not find any evidence it was ever used, almost like it never left its box. Except the tripod socket. That was worn out significantly for the first quarter of an inch as if the previous owner had misthreaded in a tripod plate and proceeded to keep twisting, cross threading the socket.
I don't really use the tripod socket much anyways as I typically use the socket on the larger lenses, but I do use a battery grip. The clone battery grip I ordered would not catch the threads as the tripod stud on it wasn't much longer than 1/4" deep.
A local trusted shop quoted me $180 to replace it but I feared unsealing the body would cause more trouble that it was worth. Newer bodies tend to have all sorts of adhesives and gaskets.
I did however find a simple patch for now: I stripped a bit of 24AWG copper from an old solid core Ethernet cable and wrapped it around a 1/4" 20 bolt. I then gently threaded this copper spiral into the tripod socket of the camera, then threaded the battery grip stud in behind.
Basically creating a crushable thread insert. Of course there are commercial versions of this as well as industrial fixes like tapping out the hole further but you don't have a lot of margin in there. This solution seemed to work for now.
So far the fix holds the battery grip fairly solidly. I've used it for about five months and several shoots. This temporary fix lets the grip thread on with no wiggle, keeping the power and control connector near the battery stalk inline with the socket on the bottom of the R5.
I don't know if I trust using the combined grip socket plus this temporary fix, but I never really trusted using the grip's socket anyways, even with the Canon official grips. On previous cameras I always felt I couldn't put the combined camera plus grip onto a tripod using the grip socket. Disassembling an older Canon grip, I found the tripod stud held in by a fairly thin stamped sheet metal plate.
Anyways, your mileage may vary, but it might be helpful in a pinch.
