I'm not sure I buy into "adjust the drag...on the fly". I always get the drag right where I want it, then lock down the clamps onto the rods. With those clamped properly, the screw has no influence on the fence position...in or out.
I really like the Mortise Base. Kody did a great job of making it work with any router base that accepts guide rods. Just to share a little history on how it came about, The linked video shows the shop built version I came up with to demonstrate our metric mortising bits. That got the engineering department's gears turning.