Koozies are usually screen printed, im guessing you could apply vinyl to them but i dont think it would be a heat applied vinyl.
Someone else will probably know more but im a screen printer and happen to know that koozies are usually screen printed.
i have a summacut d-60 connected via usb from what i understand this method is only possible via parallel connection which my pc does not have.
im looking into buying co cut or sign cut another program i am trying out right now.
i also have the option of getting flexi 7 for $500...