I make great use of the fillet tool, including all variations except the drag knife option (I don't have a drag knife). Most often on square corners of pockets, but occasionally on acute and obtuse angled corners. The two options (dog bone, and t-bone work fine on acute angles, but on any obtuse (between 90 and 180 degrees) intersection they both overcorrect. The dog-bone fillet option moves the bumped out arc farther off the original intersection than it needs to to make clearance for a sharp corner to fit into the pocket. The T-bone fillet should stay tangent to one side of the intersection, but bumps past both sides on obtuse angles. Try it on a 5 or six sided polygon to see.
I'd love to see these two options optimised to only bump out as far as needed on obtuse angles. The value of the T-Bone fillet is lost on obtuse intersections. The dog bone should be an easy fix/calculation. When the angle is obtuse, bisect the angle then center the fillet arc the radius length down that bisecting line. The algorithms currently used don't work best when the angle is obtuse.
Just a request. Thanks for considering.