I use a JIS square taper BB with my Sugino 75 cranks, and it works fine. I have uninstalled and reinstalled the cranks a handful of times or so, and the chainline is still straight (the cranks are still sitting at the same place on the spindle). I don't use a torque wrench to install, but I just try not to overtighten them.

If you find yourself flexing very hard and a vein is popping out of your arm when youre torquing your bolts back on, then youre probably over-tightening...