Has any member out their familiar with this modification on Cone baffles, photos are from a listing on Sturm board on stainless cone baffles, any ideas on improvement with this mod ?

Just the run of the mill single clip using a ball nosed end mill. Clipping is a must do to get the best results.

For this design, there isn't any commonly used improvement.

If the skirt was pulled .25" in from the OD, then you could port the opposite side into the co-axial space. (Known as a "mouse hole.")

But this design doesn't offer this option.