I want to make my internal space solely for app installation and then the rest of the data (e.g. big game files, etc) I want to go to my external SD instead. How do I do this with a fully rooted phone with Xposed framework and recovery and running Lollipop 5.1.1?
I'm answering my own question here now. What I ended up going with is the Xposed module called XinternalSD. What it does is trick the apps of your choosing to think the external SD card is the internal SD. You can choose which app to redirect so things you want to be faster (like a launcher) can be kept pointing to the internal. This module can also work on system apps so that's really nice. For example, if you set Chrome or Firefox to be redirected, when you download things, it's gonna go directly to external SD.