No set screw on this one. In the article he mentioned cutting the spring.
If the mark really doesn't get worse, like digging into the slot, then no worries.
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"One last treatment for the Gas Baffle is to take both ball bearings out and shorten the spring. This though is tricky and I do not recommend it. First time I tried I lost all the parts and had to source some new ones. It is something though that I am going to add on to the entire process soon."

Wasn't a problem getting the balls out and back in. Just didn't want to cut the spring without a replacement available.
I deburred the edge he showed.