Here is the result
How does this come into play for a failure that occurs long before that link cams over to move the barrel up into the grooves to lock up?
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Because it's slowing down the timing sequence. The slide stop is "bumping" on that hump which causes a little bit of a stall, enough to slow down the timing needed to feed the next round.
There is a good possibility that there are other contributing factors as well. The feed ramp in the frame itself may not be deep enough which causes the round to stall a little coming out of the magazine, then the slide stop bumps, which causes another stall. It looks like the bevel on the link is chewed up a little bit, which could be a burr somewhere in the channel between the barrel legs and that can cause a little drag.
I saw you had checked extractor tension so I won't mention that. But, that is also a big contributor in failures to feed.
All of these things add up and eventually cause issues with feeding.