Google APP Engine (Standard) Setup

Hi Guys, 

I had v4.04 of CI working on Google APP engine by setting the writable path as /tmp/ on a previous project.

I then created a new project and downloaded a fresh copy of 4.04 and tried the same... but no go. I then grabbed the previous system and application folders and replaced them and there were a few code differences highlighted in Git using Tower and it worked... 

Any idea what's going on here? 

Is there a way to change the writable folders to say a Google Storage Bucket for example? (caching can be done easily via memcache) but the other folders seem to create issues beyond my skill level.

Did you ever get this sorted out?  I am trying to do that same.