This remix is for Aussies who will likely use Bunnings sourced shelving.
"Flexi Storage Home Solutions 16x200 Shelf" will fit this perfectly (as that is what I remixed it for).
They are available in 600, 900, 1200mm lengths.
The actual product dimensions I found were a tiny bit different than advertised (15x201mm).
So the printed gap is 15.5x201.5mm for a snug fit.

The original was 9 walls and 5% infill.
I went with 5 walls and 3% infill to save filament and time. Plenty rigid to hold some shoes.
If you dont like the honeycomb, it looks good with 5% Cubic infill, and will also likely be a little more solid.
I have made presets for both.

5 Wall Loops

3% Sparse Infill - Honeycomb

0 Top Shell Layers

0 Bottom Shell Layers

90* Infill Direction

Obviously you can use whatever infill and wall settings you want.

Printed on P1S:

0.4mm Nozzle

0.2mm Layer Height

FILAMENT COST - 130-150g
PRINT TIME - 3H
PLA/PETG