Rice cookers are not sealed for high pressure (they are in fact not sealed at all, just like regular pots and lids, because they need to lose excess moisture) and they are configured for this one particular thing: every rice cooker is calibrated for a fixed serving of rice (or couple different settings) with fixed amount of water. All it really does is turn off at the perfect moment, which is determines by weight. which is determined by a thermostat (magnet-based in this case)
Oh, I have a pressure sealed rice cooker, but it’s the top of the line Zojuroshi and is more like $600. It’s also not fast, takes like an hour, but the rice is divine. Sadly, I rarely cook rice. I got it for my sister, who lived in China for a while and used to eat rice all the time, but then moved into a tiny house and gave it back to me… I can’t really bear to throw it out - but I only use it if I’m making a huge amount of rice randomly.
