Pinning will help any gun, but it has much less of an impact with the cantilever guns because the scope/mount/barrel are all together.
For me, it all depends on what I want to do with the gun. If it is a slug gun that will only be a slug gun and I really want it to shoot, I would go all out. The thing you should keep in mind though is that with rifled barrels you get a benefit from pinning, etc. because the potential is there. With the tactical model you mentioned, it is just smooth bore, so the accuracy potential is much less. From the looks of it, the tactical model with the scope mount is more ment for an Eotech or Red-dot.
It all depends on what you want the gun to do and how specialized you want to make it.
