Is this all really a concern for people with lower threat models? It seams like a lot of effort for a pretty low risk. Although i don't know how common it is to get your devices tampered with.

I'd never heard of the glitter nail polish, so I looked it up. It would appear that it is possible to defeat, though extremely difficult and tedious to do so, and was done in 2018. Basically by separating the polish and substrate material using a combo of heat and chemicals, then gluing it back on with clear nail polish in the same orientation.

Again, crazy difficult, but you could also just epoxy the case shut.