To me semi-auto means that the meter is coupled with aperture and speed settings and that metering is done without stopping down (unlike most of M42 cameras for instance). This is how this type of cameras is defined in some countries.
Regarding OM camera behavior, I am aware of it as I own OM cameras since 1983.
I think that I recall that sort of use of semi-auto as well - from about the time of the Olympus FTL
“Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”
Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2
I put one of those "grip adapters" on my OM-4, and it helps. I have since put winder-2's on all my OM's, no more problems with them feeling small. Naturally, if you hold one properly you don't have that, as you are supposed to rest the body in the palm of the left hand and gripping the lens, whilst the right is for shutter release and film advance, not a death grip..
Yes, of course, but not having anything to hold onto doesn't help for carrying the camera in the many minutes or hours you're not pushing the button. :-)
I always carried my OMs in my left hand, by the lens, under the body. It's an easy lift to the eye while bringing my right hand to position. Typically I have the strap wrapped around my left hand for security.