I found a permanent fix for MMCX connectors that are wobbly inside the SE846. I had to transplant the super thin small gold plate from the stock cable, inside my silver cable. It's very snug now - no longer spins freely as stock cable and there is no more wobble.
I literally spent 30 mins trying to get both MMCX to cut out and no luck
The looseness happens because the groove that the locking ring sits in, is deeper than the locking ring itself. The thin gold plate from the stock cable acts as a spacer and thus keeps the locking ring very snug in it's groove on the male MMCX connector (cable side).
P.S I'm awesome