I've rarely, if ever, had squealing problems with dual-pivot caliper brakes (both short and medium reach), so I don't bother to toe them in. I have, however, never owned a cantilever brake of any type than did not eventually start emitting an ungodly shriek without frequent toe adjustments, even with Kool Stops, fork crown mounted cable stops (supposed to shorten the mechanical feedback path) different rims, different forks, etc. Which is why I now have discs on all my fat-tire bikes (touring, cross/gravel, etc.). I'm pretty happy with dual-pivot calipers on pure road bikes though, except in the wet.