Is there clear space around the back of the rock structure or is it against the back wall?
Leaving space at the substrate level enough for the fish to easily swim around the entire parameter of the tank is a almost essential, pick rocks to go on the sand bed that can act as supports for the other rock.
Maybe open up a couple of spaces so there is free swimming area from front to back.
remember, when they say 1.5-2 lbs of rock per gallon, it doesn't all need to go in the display.
I opted for less rock work in the display and use tons of rubble in the sump and refugium.
I still have 1 ~ 2lbs/per gal + total, but in the display I used only cherry-picked pieces that allow a nice open scape.
I even made certain that that "caves" are off the sand about an inch in back so water can flow through and nothing gets trapped.
since rescaping with maximum water circulation in mind my water quality has increased noticeably.
I like what you have, but it looks like you need to open it up to allow better circulation.
(excuse the container, my large and nasty brittle star in solitary confinement.. LOL)