"I'm interested in creating a portfolio of open source appliances." Yes I'm very interested in that idea too. One thing I think is vital is to separate the UI

"I'm interested in creating a portfolio of open source appliances." Yes I'm very interested in that idea too. One thing I think is vital is to separate the UI and any smart features from the rest of the device. For example, cheap induction cookers have a single mcu which has the code for running the induction heater, and also runs the UI, with just a cheap display/button board as the physical interface. This mcu package seems to be at the heart of a huge number of brands, which are all then stuck with the same terrible UI. If the ui was running on it's own mcu, talking spi or whatever to the main controller, makers could differentiate with their own UIs. And hackers could hack.