Technically yes, but not a significant amount (unless you really slather the stuff on, which is just poor craftsmanship)
Plasti-dip or electrical tape would only add a fraction of a mm of thickness - and even then, only to the bright white lettering - a tiny fraction of the camera's surface area.
Think of it this way: The major heat problem for dash cams is not what covers the camera, but the Sun (and your car's interior). The car you drive (and where you park) would have a greater impact on the heat of the internal electronics than an coating that covers maybe 5% of the camera.