Question about AAS load asset

Question1:
Is is possible to do this?

I have 2 AssetGroup in my AAS settings
GroupA and GroupB
GroupA set as Local Load path, for example: Assets/Content/Prefabs/
GroupB set as Remote Load path, for example: http://server/Android/

I have 2 prefabs in this AAS settings
ItemA.prefab and ItemB.prefab
Set ItemA into GroupA, named it as ItemA
Set ItemB into GroupB, named it as ItemB
But, I don't really have ItemB in my project, it was created from my resource project.
That means, my ItemB AssetReference's path is empty now.

So, is it possible to load both Item prefab in my game now? in any mode~
I did tried a lot of ways for realize this, but I can't get it.

I mean, I wanna load AAS asset with both remote and local way at the same time, I called it as MixedMode

Or, is it possible to set GroupA run as Fast Mode, GroupB run as Packed Mode.

Question2:
Is it possible to disable AssetBundle rebuild? while play with Packed Mode on Editor.
If it is posssible, how ?

Question3:
Is it possible to rebuild only one AssetGroup via AAS window?
Or, will AAS skip packed file in AssetBundle, and just update file that has been changed?

 

In short: I need GOOD split project tutorial