Better optimized terrain importation?

This is really something of an experimental question. I am trying to push the limits of Roblox

I am currently trying to get an extremely large area of terrain in my game, but I am running into some optimisation issues. I can see clear ways of how I can improve them, but they are really tedious to do manually.

When importing terrain normally they are always generated with terrain underneath the surface. I think this significantly reduces the amount of memory left for parts that you’ll actually see.

So my first solution was this:
is there any way to generate imported terrain without any extra underneath?

I tried looking for alternate terrain importers but they were way too bulky and hadn’t had the type of options that I was looking for. Does anyone know how I could do this, or if it’s possible at all?

Alternatively i’d like to know of any other ways terrain could be optimized, as I’m sure there are more. This was the only fairly simplistic solution I could think of though before going too in-depth.

Thanks for reading, and I’m looking forward to seeing your answers

PS: i wasn’t sure where to put this topic, it was either in scripting support, game design or building. but hopefully this was the right choice.

Maybe, on the command bar, do the same thing as you would from generating terrain with parts but instead of parts use terrain.

But, this would mean that you wouldn’t be able to import your terrain.