I think all the B&Qs have rebranded to i-house now. Basically the same thing though. There’s one in Yilan and one in Hualien County/City.
Costco delivers, but I don’t think it includes fresh foods. Also, don’t think they deliver to hualien. Really never checked. Carrefour might but you probably have to go there to do your shopping and arrange delivery with them. You could also do your shopping in person at Carrefour and get 7 Eleven to refrigerate it and deliver it to your place.