My recommendation and the way I have accomplished this is that on each of your devices that differ in screen size, you have a totally different set of panels. For my 5.5" z Force Android I have a complete set of panels that work together and are sized appropriately for that device. You can see my screenshots of how I have this setup up in the official ActionTiles thread out here from a few days back.
As for my 10in tablets, I copied all my z Force panels to new and created a different layout with appropriate sizing for tiles and settings as to how to display them on those devices.
The way they built the foundation, there is no dynamic resizing that takes place based on screen size, without going into Settings and changing the Tile size for that Panel on the fly. Maybe someday it will have a one size fits all. 
Here’s a link in another thread I posted my layout for my Android panels:
And make sure when you are laying things out and viewing the panels that you take Full Screen into account. When viewing go to Settings / Full Screen as that’s ultimately how you are going to want to display your panels and that changes the landscape.