Personally, I wouldn’t go shorter than 80-90mm on a road stem. I noticed a big difference in twitchiness going to a 10mm shorter reach bar with a 100mm stem. Mind you, I ride an already very nimble bike (Allez Sprint), but my feeling is, if you get down to an 80mm stem, you probably need to look at going down a size on the frame.

I’m 5’9.5” on a 56 with 100mm stem, at 6’, I’d be surprised if you had reach issues on a 58 with a 90 or 100.