great questions!

- knob: yeah, if I were to redesign that part I would move it to the top. I had a total schedule of 4 weeks for this project, and I didn't feel confident enough to rebuild (and print prototypes) of the case when I encountered the weight problem, but that would definitely make it better

- I did fillet/chamfer (almost) every edge I believe, I also printed the final case with fuzzy skin to make it feel higher quality

- The knob was originally meant to also allow you to change the timer, so having a dial felt like the right thing to do. Didn't turn out that way, so yes three buttons might be the better UX for the menus I ended up with (and would make the device smaller)

- The shroud actually started out as a way to prevent light leaking (and then I re-printed it in white so that it would boost the LED diffusion a bit together with the diffusion plastic film), but I like your idea of having an LED strip around the edges of the screen - didn't think of that!

- I am usually more of a Blender guy, so I followed a tutorial for doing knurling in onshape. The tool really doesn't like that much geometry and is laggy to work with, but feel free to check out the onshape file (linked in the README)