[TheAmishStig]

Seems to me, the whole argument over real-world fire control systems and their relevance to Ogre hinges on one simple question:

Is "Clear" terrain in Ogre flat?

I would posit it doesn't have to be; by the terrain rules in GEV/ODE/etc, it only has to be just flat enough to not meaningfully impede movement the way a ridge or water would, just dry enough there's no meaningful risk of bogging down the way swamp would, and just clear enough of debris that there is no meaningful danger of crashing into something the way a forest or rubble would.

If there's one thing I learned from games like From the Depths (a cross between Minecraft and Starmada), it's that you don't have to jam your opponent's sensors or even take cover if you can out-track their turret. I nearly lost a battleship to a frigate that way...it was able to out-track my guns until it could get under them, and only by building a short-range missile system on the deck [while under fire] was I able to get out of it with FN-215 still floating.

OP, have you looked into the 'Camouflage' rules? House-ruling a tweak on that so that an exposed unit can return to 'hidden' status (say, after 1-2 turns of not moving / not firing / not being fired on), and/or one where hidden units can only be attacked from adjacent hexes (Size 5+) / must be overrun (Size 4-) could very well solve your problem without negating the reason GEVs exist in the first place [the ability to hit-and-run without risking counter-fire unless the opponent wants to run them down].

There's going to be a lot of edge cases and things to work out...like whether or not it's reasonable to allow an Ogre to hide at all [which is the Ninja's whole shtick, possibly conflicting with 'purity of purpose'], whether or not it's reasonable to allow immobile units [disabled Ogres, Howitzers, buildings, etc] to 'take cover', whether or not it's reasonable to allow 'saturation fire' (attack strength of say, 6+) to fire on the hex anyway as an 'anti-camper' measure, what to do if there are units stacking in the hex [hidden or visible] because of spillover fire, etc...but that seems to me to be a lot less damaging to the intricate rock-paper-scissor chains that make Ogre, Ogre, than something like allowing out-of-turn fire.

At that point the other player has a tactical decision to make: Is the area you're denying worth going through?