Generally, I agree—if not fully bioactive then no substrate at all. It's the definition of "no substrate" where I may vary, and what I did depends on what mfr./model or DIY enclosure you have.
My enclosure came with 2 floors (either/or)—a piece of solid sheet PVC, or a screen panel.
Since I have all live plants (in pots) and mist more often than many, I used the screen panel, but I placed that on top of a piece of
ceiling egg crate cut to the same size. The egg crate distributes the weight of the pots so they don't damage the screen, and the screen allows water to drain through to the drain pan, keeping the "floor" dry.
I vacuum up any debris &

weekly, and spot-spritz any soiled screen with
Nature's Miracle, which breaks down the

and eliminates any odors.
You may find some other ideas in the
Drainage thread.