How to repeat a spatial unit in a memory efficient way?

Hi guys!
I need this spacial unit to be repeated a looot of times during the game, with just the video changing.

When I selected all the meshes that make it and make a BlueprintClass out of it, they all disappear.
When I start making a new BlueprintClass with those elements, I can’t make it that way - I can only add StaticMeshes and Cubes that can be resized ONLY through scaling, which means the materials get stretched (during scaling). Also, I can only add Additive, and not Subtractive cubes/meshes.

So: how can this spatial composition be repeated through game without using separate memory every time?

I have also thought making this space a Sublevel, but I haven’t found a way to repeat a Sublevel inside the same Persistent level.