I’ve done exactly what John has suggested with my M80 center here in my house. Whenever I’ve put my mains up on milk crates to elevate them. Having the mains a little higher (above furniture) seems to help them better fill the whole room with sound and blend better with the surrounds but that assumes having an open area behind the seating. From what I’ve noticed the center channel doesn’t seem to benefit from this plus it’s under my screen and can’t be elevated. Tilting it back so that the drivers of the center that correspond to the drivers on the mains that are nearest ear level are pointed at my ears keeps the timbre even across the front. Though it goes against conventional wisdom in my experience it’s actually more important to have the midrange divers near each other than the tweeters, though when you have one you usually have the other.
Keep in mind that you can always mount a speaker upside-down. I’ve done that when demoing my M22s against my M80s. I just put them upside-down on top of the M80s and they sounded no different than when right-side-up at the same level. I also ran my M80 center upside-down above the screen in relation to my right-side-up M80 mains. This worked great with no variations in the soundstage as things panned across the front. I actually prefer this arrangement because it produced a “wall of sound” (due to spreading out the drivers vertically) but w/o interfering with the horizontal placement of instruments and singers in well made recordings. It does create a slight vertical effect which in some recordings made it sound like the vocalist in the center channel was on a dais, but it was subtle.
In your case if the center is right-side-up under your screen I would try putting the mains upside-down on the stands to either side. At 8 feet the same distance I was from my upside-down M80 in my apartment your M22s should sound just fine.
3M80 2M22 6QS8 2M2 1EP500 Sony BDP-S590 Panny-7000 Onkyo-3007 Carada-134 Xbox Buttkicker AS-EQ1