An enclosure for the FLSUN v400 printable in ~1.5 hours for all 3 sides. Use what you've got.
Don't waste time on 9+ hour prints for an “enclosure.”
Zip-ties, heated inserts, glue, it doesn't matter. Take cardboard, plexi-glass, fabric, or whatever and affix it to these t-slot tabs.
Big improvement to print quality.
Air gaps? Duct-tape.
Screw-hole for tension against aluminum extrusion. Likely not required; friction fit.
Modeled against: https://www.printables.com/model/378646-flsun-v400-extrusion-positive
The author marked this model as their own original creation.