There are a couple reasons we cannot readily help with this. First, in Bloom you are choosing a language, not an orthography (though it is possible to choose a language and then specify which orthography you’re using, for languages that have multiple). Second, we don’t maintain our own list. Instead, we just show a list that originates in Ethnologue.com. I think you could petition the Ethnologue to create a macro language that covers both?
What you can readily do is pick one and then change how the language name is printed on the books, in the lower-right-hand corner of the language chooser dialog box.