according to their bitcoin 2013 presentation the seed should be written down during first time setup, but recovery has to use software as you can't input a custom seed. I'm just not sure if using an oled was the best decision. For example, my sega gamegear still works after 20 years. Afaik the use of an oled puts a limitation on the lifespan of the device which could otherwise just last as long as it has no battery or moving parts.