Procedural heatshield' mass and cost don't increase with length

[Tonas1997]

Title. While cost and mass increase with diameter, it doesn't do so with length:

[Swamp-Ig]

Wouldn't this make sense though? The cost is the surface ablative layer, the stuff behind is just filler / insulation.

[Tonas1997]

Partially, yes. But as you can see in the screenshots, surface area also increases with length. Part volume does as well, and both should reflect on mass and cost.

[DRVeyl]

There's no tankage, so the effect of additional volume is questionable.
What would you propose the solution should be? Besides just "more."

[Tonas1997]

Hmmm... giving it a second thought, it does make sense for either mass/cost to only scale with diameter. That being said, shouldn't there be an intrinsic tradeoff in going for a thicker heatshield? Perhaps a higher maxTemp at the cost of increased mass?