Yeah it is hard to imagine any person not willing to flash the SD themselves to try out an OS like this.
I can imagine building a hobby, niche unique OS and then other hobbyists installing it themselves, but not what OP is seemingly trying to do.
He is spending time trying to figure out how to send an microSD and all the regulations of selling an electronic device instead of simply building the OS. It seems quite backwards to me.
Based on the articles it seems like he has been spending months on this. I don't know... just build the OS and develop selling points...