Part of the effect of a bbl mounted comp is the added weight resisting the action unlocking, similar to how a heavy suppressor prevents cycling without a Nielson Device. A ported bll will reduce muzzle flip a bit, but may not reduce the slide velocity much. Also might be some crud buildup as the ports vent while not aligned with the cutouts.
If you have a mill, why not just make your own bbl mounted full profile comp? Comp Blank - Full Profile 2" Carbon Steel: EGW Gun Parts
Or cut the bbl bushing part off the one you have and sleeve it to thread on the end of the bbl and bore it out to just over bore diameter and make it a real comp?
They still make a few full profile comps, but they are pricey. Cylinder and Slide and TJ's Gunworks both utilize them in their custom pieces, should be able to purchase them as parts.