There isn't enough detail of the boiler to tell if there's an overpressure relief valve. The boiler can't be made safe without one. If they're cheap enough to be standard in cheap knockoff moka pots one should be here...
This machine's wiring diagram shows an unlabelled shape wired in series with what might possibly be the heating element and a shape with "ssr" in its label. Which places the first unlabelled shape in the right place to be a thermal fuse or switch. If they're cheap enough to be standard in Mr Coffee machines one should be here...
Safety discussion in this project is conspicuously absent. Knowledgable users shouldn't be making assumptions like this about safety features. Assumptions and safety aren't compatible. Average users should be informed in detail about the safety features they're tasked with assembling.