Have you looked at other high quality toaster makers abroad?
Dualit is in the UK and has been manufacturing high quality, hand built toaster for a long time, but most consumers would balk at the prices they ask for their appliances and I doubt you as a startup would be able to manufacture a toaster any cheaper.
https://www.dualit.com/collections/classic-toastershttps://www.dualit.com/collections/spares
Frankly, I don't even own one, in spite of being a champion of the "buy it once" mentality. But it's on the bucket list.
I have a dualit toaster and absolutely love it! You can get spare parts for it and repair it yourself. To me it's worth the 3x premium of its the only one I ever have to buy in my life.
Yes, the timer is a bit loud and you have to think about how done you want the toast ever time, but it becomes automatic, i.e. I just know what the right setting is for a bagel.
Only played with it for a little but it seems well designed an simpler alternative to ansible, chef and other such things.