Lotech: Thanks for the comments. I've tried both a mortised and un-mortised wood inserts using sliding bands/slide ring seats. I think that the mortised inserts offer a little more security and they do help prevent the reel from slipping/spinning around the seat. I think this is even more true when I use cork inserts as I cannot tighten my rings quite as much when the insert is made of cork without damaging the insert. However, mortising an insert can be difficult unless you have the right tools and have some decent wood working skills (which I lack both).

My mortises are sufficient, but they are not perfect by any means. I have created my mortises by taping off the dimensions of the mortise using masking tape and carefully (*VERY CAREFULLY*) using a dremel to start removing some of the wood. Then I hand sand the remainder until I can get the ring to slip over the reel seat foot securely.

The hardware set that I'm using on this rod is from Joel Lemke and the uplocking ring that is housed in the inlet of the grip creates kind of a pocket....so my "mortise" does not have to be too precise. Then the back ring just needs to be able to clear the reel seat foot and lock the reel forward.

You asked a great question....one that I've played around with on the last few builds. I have recently built a Sage TXL and another Orvis Superfine Touch 663 that both feature dual sliding rings. I did a mortise on the TXL, and I tried the SFT 663 without a mortise...but I ended up going back and adding one as I preferred the seat with a mortise. I think the mortise is even more important with dual sliding bands....but that's just my opinion.