So, have you looked into how Sandstorm packages files, and whether one of your JSON manifests could be easily added next to a Sandstorm package in order to run it? Or, oppositely, could your platform install an app based on a provided SPK file (and it's own built-in manifest)?
The biggest difference is that it looks like you have people include a script to install the app, and Sandstorm packages the app and all it's dependencies 'pre-installed', and is mostly independent of Linux flavor.
Since Sandstorm packages have all the dependencies and app data in read-only, and all of the user's app data in /var, I would think it'd be relatively possible to figure out how to get the two formats to play nice.
The biggest difference is that it looks like you have people include a script to install the app, and Sandstorm packages the app and all it's dependencies 'pre-installed', and is mostly independent of Linux flavor.
Since Sandstorm packages have all the dependencies and app data in read-only, and all of the user's app data in /var, I would think it'd be relatively possible to figure out how to get the two formats to play nice.