differing permission handling

I've noticed on oldish HTC One, this statement (in the README) is true:

The plugin requests user permission to use persistent storage at the application first start.

On a newer Nexus, the app doesn't prompt for it at load time, and it doesn't even prompt for it the first time it's used. Further, even after denying the permission, methods from CordovaFileCache.js still seem to work -- download/get/ready/toURL/clear all fine.

So, what exactly is the file permission doing? Is there any way to entirely avoid it?

instantiating CordovaFileCache & CordovaPromiseFS here:

  cache: new CordovaFileCache({
    fs: new CordovaPromiseFS({
      Promise: Bluebird,
      persistent: true
    }),
    serverRoot: $server_hostname + '/assets/',
    localRoot: 'data',
    cacheBuster: false
  }),

[markmarijnissen]

What README are you referring to?