Asphalt Concrete Line issue (Add more custom forms?)

[IcedForge]

White Line block ramp blocks does not merge correctly with regular white line blocks.

White Edge Border Ramps does not merge correctly regardless of block below it

[keegan-o]

I've investigated this, unfortunately neither problem is easy to solve since the category rule style is not available for road blocks since they must all merge with terrain. Adding it explicitly in the rules will be looooooots of rules, so I'm asking if we can get a second category slot for blocks instead to make this much easier to implement.

[Thibault-Brocheton]

Confirme the issue still there in 0.9.1.4 (I understand it's just medium priority, just putting an update)