default gaps for arrangeSystem

I'm using Simulink.BlockDiagram.arrangeSystem function to beautify my simulink subsystem layouts.

most of my blocks are already arranged well, but with a narrow gap between blocks. Only several blocks and lines are disorderly.

After I run Simulink.BlockDiagram.arrangeSystem, all the blocks will increase it's gap, and became a messy with more lines crossed and block lapped.

Can I setup a mask for the already arranged blocks, or can I set the default gap for a narrow one before I run the function?

Thanks.