Partial thoughts (because I've been distracted by fighting with my bank to get a 'suspicious activity' flag resolved so I can get the rest of the stuff I need to repair the heating system in the kitchen):
Now I see where you're coming from. Thank you, that was bugging me...and I see the argument at play: not "These are beyond the complexity level of Ogre", but "These are beyond the scope of the rules tier (as you've defined them in 'where you're coming from') being suggested". Cool, I can work with this. If it was just related to M2, we wouldn't even be having the conversation, because of how unique that map is.
For what it's worth, I'm thinking in terms of "As part of translating this rule that is currently specific to a scenario and its special map into something to be used for overlays, included on G4+/S4+/M6+, etc...is there value to be had in loosening the movement restrictions to allow a subset of units through, and if so what form would that take to make them distinct from already-existing terrain types".
Personally, I think there is...not unlike how the movement restrictions on a Forest open up the possibility for Heavy Tread units to go through while GEV craft go around, and the tactical headaches that presets (able to 'scrape off' GEVs, or catch up to a set that's trying to get away).
And as long as we're fawning about the abstracts that make Ogre able to survive 40 years...I really, really appreciate that it has a small but powerful glossary. Compared to something like Alpha Strike, Ogre has an extremely minimalist set of keywords, which makes it really easy to communicate both new one-off terrain and 'quick reference' tables...off the top of my head, terrain has only 8:
- Prohibited: Unit may not enter / pass over. Prohibited units that find a way to enter (such as via bridge destruction) are destroyed.
- Delayed: Unit must start its turn adjacent to enter / cross.
- Slowed: Unit must pay 2MP instead of 1MP to enter.
- Disable Chance: Unit must roll to avoid becoming disabled; movement ends.
- Stuck chance: Unit must roll to avoid becoming stuck; movement ends.
- Defense Modifier: Unit receives the listed change to its D rating.
- Blocks LLOS: Lasers cannot fire over this terrain feature.
- Destructible: This hex has special case rules for when it is attacked.
That's it. Unless I've missed something, those 8 traits cover the entirety of the official terrain effects ruleset (Mountains via Iron Mountain add a 9th: Blocks LOS, no unit can fire over this terrain feature). Every hex, every hexside, applies (or in the case of beaches, removes) them in one combination or another.
That in turn is how I came up with the language of "Infantry delayed, others prohibited" and "Infantry Slowed / Defense +1, others prohibited, blocks LOS, Destructible".
For the time being...let's completely sidebar the 'Destructible' conversation for now, 'cuz I think we can have a good conversation going about just the rest.