Room Procedural Generation and Random Floor and Walls Population

Hello guys.
So this is the idea I want to implement.
I want to implement a game with like 100 levels. The user will go from level (room) to level, and each level will be randomly generated, so like one can be rocky, another a spaceship.

What I have now is 3 Levels, this will unload and load in front of the player as he goes. For this I created a grid system (chessboard style with one room 32x2 / 16x4 / 8x8 of cubes) on the construct script.

Then on begin play of the blueprint I will switch the cube static mesh with another static mesh from free assets or texture.

What happens is that the mesh as they are different size from the cube, not 1x1 will make everything weird, and If I change them to 1x1 it will be very boring, as for the textures they do not mix together.

How should I implement the alogrithm of the room creation and population so it is interesting?

Example of what I have.

First Image room after construct script.

Second Image room populated, floor with static meshes as they have different sizes they overlap, and the walls have texture and they don’t mix.

Hi man, i think that making meshes of different size will end in a mess, you should calculate the amount of space that remain between the meshes and fill them up.
there are surely a lot of ways to fix it.
Why dont you use the legendary Tiles concept ?
you fill the room with smaller meshes and use every mesh/ texture as a part of a set of tiles, to give any particular Style any shape.