I see your point. I may release installable native apps that can serve as the local storage backend for the truly paranoid. Time limitations etc: the usual. :)

I anticipate that PurpleRails will be used on multiple computers and over several years. Which is why pages are sync'd to the cloud.

I've adopted the current architecture because I feel that the energy barrier that needs to be overcome to persuade somebody to install an app is much higher than the one to install an extension.