Hi
There is already such an option, in the startup options - If you load up the mod on its own, you should see an option called something like "Use new crater tiles" - disabling this will cause the mod not to add any new tiles.
This does lock off some of the larger nukes (actually they might just crash the game - I can't remember whether I remembered to disable them), as in everything 100kt or above, unless you disable the "optimise 100kt" and "optimise 1Mt" in which case they will work (I'm pretty sure) - though everything above 1Mt will still fail, and the 100kt and 1Mt will have vast performance requirements.
However doing this does remove some of the effects - the craters look very flat, and the water filling is quite primitive.
I don't guarantee that future features will work without the new tiles - I'll always make the mod work, but not everything will be available.
Most other mods which add lots of tiles have some similar setting (I know Alien Biomes and Asphalt Roads do), and as I've said above, not everything can be done without adding tiles in this mod, so I would advise checking out your other mods compatibility settings - it might be that there are some added tiles which you have no intention of using.
Hope this helps