Change/Remove Landscape collision at run time

I’ve managed to get positional alpha masks working on a landscape which allows me to make square holes in the terrain at any location or rotation (see below):

At the moment, I haven’t figured out the issue of making multiple holes, but the thing I’d like to tackle next is landscape collision. Is there a way to overwrite landscape collision at run time? Ideally, I’d be able to choose a volume (using a box component) which allows the player to pass through the terrain within that space.

I’ve also tried a more hack-y way of turning off landscape collision when the player enters a trigger volume around the hole, but the collision doesn’t change.

Is there any way to disable or change landscape collision at run time?

Were you ever able to find a solution to this?