The only reason that I bring up the superfortress range thing is that unlike the normal AI fortresses, AI superfortresses did not receive a nerf to their range to compensate for their buff in HP.
I will admit though, this does introduce an interesting dynamic. It effectively makes the planet off limits to anything but polycrystal armoured units (most notably, bombers). Something that the current AI normal fortresses do not; those "merely" limit a decent portion of the planet off limits to non-polycrystal.
Though I wonder how you would take a planet with a superfortress and lots of units that counter polycrystal stuff.