Yesterday I added support for opening existing website projects in addition to the existing support for creating new websites. So far I tested it with opening directories from local storage or iCloud and it works great!
…and I’ve been testing regular iCloud sharing for collaboration since before the HyperTemplates launch and it seems to mostly just work™?! I suspect we’ll need a dedicated sync engine at some point – perhaps as a premium feature – but I would guess that iCloud sharing will work just fine for most use cases.