Yeh it works much better using something to rise it up. It evenly distributes the weight of the scape on the bottom and gives it a much nicer look and more of a natural scape. I have even seen some people put bio media in the riser. I just put a mixture of lava rock and river rock for bacteria growth.
Here’s the one I bought
12Pcs Aquarium Fish Tank Divider... https://www.amazon.com/dp/B08Q7YV8X6?ref=ppx_pop_mob_ap_share
The tension at the bottom was the main problem I couldn't figure out with that design, so I will consider what you said about it.
I asked this in another sub and they said to use tank dividers with suction cups to hold it in place. Something like this, and to just heat it up and bend it so that it forms a curve that'll fit into the corner. What do you think about doing it that way?