This method is not needed if you have more than one collision box.
This will apply the correct collision boxes.
What you are pointing out is the selected bounding box. You have changed the collision bounding blocks.
You can override getSelectedBoundingBox(IBlockState, World, BlockPos)
To return an AxisAlignedBB to change the drawn outline. However, if you need to have more than one box drawn...
And
Finally,
This isn't necessarily true. Anyone can get the "Forge Modder" tag if they want it. However I have probably spent more time within Forge/Minecraft code than he has. But I haven't done so longer than many more people on here, IE draco18s, diesieben07, etc. They definitely have also spent more time programming than myself.