It is always a good idea to give some context to your post - otherwise confusion reigns...
You seem to want to ambush me with an unanswered question of some months ago in another thread, about a completely different tool...
I am not clairvoyant.
I see your 2dTools Fillet issue, but I am not going to fix my code. It's well over a decade old and it already has issues with some other of its tools in the latest versions of SketchUp.
It is free-ware after all...
But if you want to adjust my code please feel free...
In 2DfilletTool.rb... in lines#380 and #386 remove the # so the edge is erased... works for me.
On reflection, I've posted the corrected RB file in the original thread, which you should substitute in the 2Dtools subfolder and restart SketchUp to sync.
It will break the 'signing' but provided your Extension Manager's Loading Policy is set to 'Unrestricted' it will load OK...