You can get around that by putting a piece of tape over the density detect hole. (That's the hole in an HD disk opposite of the write protect switch.) The real problem with using 1.44mb floppies as low density is they're just not particularly reliable when formatted like that. *How* reliable depends on the media, the drives, the phase of the moon... etc. In my experience my M0106 drive seems to "mostly work" with HD disks, but the internal 400k drive on my 400k is much more skeptical of them.
Fair warning also: The original 400k drives, or at least the one in my machine, seems to have a "disk-present" sensor that shines right through the density select hole, so the internal drive doesn't see an HD disk *unless* there's tape over that hole.