Lowering Planet Quality instead of increasing?

Basically I want to create a new Project like Aid Economy that on completion will lower the planets quality but gives strategic resources in return.

I've looked into using the terrforming action:

<PerformAction>

          <Action>TerraformTilesOnPlanet</Action>

          <ValueParam>-1</ValueParam>

          <ValueParam>0</ValueParam>

        </PerformAction>

In all possible instances but that typically results in a planet maxing to 63 tiles and... that's the opposite of what I want. So instead i've been looking into the Invasion Strategies, namely Core Detonation since it destroys tiles+improvements but I can't find a way to implement this:

<ImprovementDestructionChance>0.95</ImprovementDestructionChance>

    <ImprovementDestructionMin>1</ImprovementDestructionMin>

    <ImprovementDestructionMax>99</ImprovementDestructionMax>

    <TileDestructionChance>.98</TileDestructionChance>

into an Action or a TriggerEvent.

Help would be appreciated!