Multi tool with decent 15mm

dr.oblong
the da caliper is actually a rear, since i put the front on girlfriends fuji, so the extended allen nut(?) on the back of the fork engages about 3mm of thread and goes out of adjustment easily (but it's not that serious).

Haveyou tried a longer allen nut? They come in different lengths and so you might be able to get one that engages better, which is what I did for the rear brake on the front of my girlfriend's bike.

what does the leathermen do for you? never saw the need myself.

Pliers, knife, bottle opener. Don't use it that often but it's useful when something unexpected happens or I want to drink.