I think we can do that. You can package your app in a one file executable and we'd download that like a windows installer. But the question for us is whether it's worth support Linux here? You need to know that our kit is not open source compatible. So only closed source projects can use it. But the people doing commercial linux development in REALbasic are difficult to find.
If a few people tell me they need Updater Kit for Linux, we will do it. So please email us.