@royazriel ,
We do not recommend doing apt upgrade, since we do not test this update method. If you want to update the SDK, you should do that following our SDK install instructions.
As an advanced user, you may select to update your apt sources to use dev releases (basically latest dev branches) and selectively install packages that you want to test.
The recommended SDK release for Starling 2 (Max) is 1.6.4
With that in mind, please let us know if you have any more questions about this.
Alex