It's a fantastic idea and I love the concept of user assembly and repair of household appliances.

I think the author has done something wonderful and thoughtful here.

However, I think a toaster is probably the least complex and least risky kitchen appliance. There are quite a few kitchen appliances that I would not feel comfortable using if I had assembled them myself. Anything with spinning blades for example. Also I don't think anyone should be assembling a flat pack microwave, where doing it wrong could end in radiation leakage.

But still, it's a great idea for less risky things. I look forward to open source hair dryers. Those things burn out in no time