Comment 6 for bug 1877585

@ltrager My plan was to implement radio buttons for each selected release where you would then select architectures on a per-release basis. At the moment the bootresource.save_ubuntu websocket handler doesn't allow this - you can only pass it a list of releases and a list of architectures. How much work would it be to update it? If it's significant I can just implement what was suggested in the original bug report (a message saying "Combination unavailable") but we would also need to make sure that error messages don't show up too.