Quick sort of non-update, but maybe a fun mod for anyone interested—
I noticed a bunch of cat hair and dust accumulating on the front grille of the L5, and a non-zero amount making it inside, so I thought I'd try and shim in a little filter.
We had a few extra filters for an air purifier (it uses a screen to catch large airborne particles, a coarse filter that feels like a ScotchBrite pad, then a fine HEPA/whatever filter for the smallest pollutants), so I cut a little 3.5x8" rectangle out and fitted it between the fan bracket and front grille. Snug, but not tight enough to interfere with the fan hubs/blades.
It seems to act as a bit of a noise dampener as well—prior, there was a bit of a hum to the fans that I could stop by firmly gripping the outer panels of the case, but… it seems virtually silent, now.
Buttoned it back up too quickly to photograph the interior, but I cleaned up the cables, as well… previously, I'd tried to tuck as much behind the motherboard tray as possible, but I found it was crimping things and making it less maintainable.
Here's a photo of the material. Thinking I might try and use another chunk of it in the panels of my DA2, and see if it's any less restrictive than the magnetic filters it came with.