Many years ago I made a small set of metric ground down sockets - 10, 9, 8, 7, 6mm, 1/4” drive. That set stays with a small pile of tools that are handy for bicycle work. You will encounter thin headed fasteners again and it’s handy to not worry about damaging hard-to-replace bits. And the lack of that end taper* does not slow me down a millisecond. I ground down a 9mm box wrench too for working on center pull straddle fittings.

* probably designed in for the manufacturer’s benefit, not ours