I did a fresh install of OS 3.1 from the floppies, but I cannot get the thing to boot in NTSC mode. (It works perfectly in PAL mode.) From the early start-up menu, I select NTSC and also the CF hard drive (my only "hard drive") to use as the boot, yet it in NTSC mode it always goes directly to the screen animation requesting the OS 3.1 floppy -- Why would it do that? Did I do something wrong during the install? I chose the easiest/automatic 'novice' option when doing the installation.
Have you tried the conventional way, ie move NTSC monitor driver from Storage to DEVS:Monitors/ and double click it, then open Screenmode prefs and select and save the NTSC mode. Then reboot, Workbench should then always open in NTSC.