Then, somewhere between the micro apartment & Trader Joe was a piece of titanium that didn't come from a grumpy old man's bike.  Because it doesn't bend, all the flexing broke it off the glue.  The scratching didn't penetrate either, so the glue was ineffective.  Thus the riveter returned.

The epoxy was an effective spacer.  Just use something which cures faster than Loctite Metal.

Given the wear on the titanium, the rivet wear didn't look as bad as before.