I admit, I've never really seen any advantage to using ordered (or unordered for that matter) lists in ebooks. Other than where it's required in say an EPUB3s nav document or something. I can see utilizing them to present live data that needs to be updated frequently--like a database front-end. Where one never knows how many items might need to be listed (and even then, that's what a php for loop is for

) But for static content that only needs to be created once; then I say number|letter|roman numeral|bullet|star them yourself and be done with it. If I type the number "1" or the letter "a", every ebook rendering engine that exists, or ever will exist, is going to display it.