Just wondering if anybody has deliberately hacked off bristles to perform any specific task or “modified” a brush for any other particular reason.
Over
Yeah, I’ve cut them off flat and cut points on them before. I’ve also cut individual bristles off. Usually happens when I mess up a brush or it starts getting so worn it’s either “Modify” it or trash it 
most definetly!! i cant stand stray hairs. i’ll reach for the old xuron sprue cutters. they work well for trimming stray hairs. other than that, i leave them be. later.
I trimmed the ends of a worn brush down to about 1/16th of an inch and they were nice and stiff. I used it to dab on aluminum paint to simulate where the original paint job had chipped off the interior of a cockpit.
All the time. I have cut-down, stiff-bristled “stippling brushes”, ragged looking “random pattern scuff-mark” stippling brushes, picked apart "gnat’s ‘behind’ " detail brushes, do-it-yourself filbert brushes for dry-brushing, all sorts of them!