Version 2 will support both the original xml format and the new ubox format.
New in Beta 2: Drag an xml or ubox file into Universe Sandbox to load it. You can now also double click on a ubox file to open it in Universe Sandbox.
I will eventually (probably) include tools and utilities to automatically create ubox files from existing xml files.
... looks like I have to start again XD
Not at all. A ubox file is an xml file zipped up into a .zip file that's been renamed to .ubox
(Microsoft's docx and xmlx files are also renamed zip files)