Mace,
Put a shim on the face of your current shock valve and look at it. If you can't see what maybe even you might consider a "potential" flow restriction there I'll be surprised (relative to load). Your shock valve port mouths are completely covered by the shims. Now do the same with your Brass doorknob. You will see a difference there, and you will see why. What he did with this thing is good. The shim deal is a good idea, but a financial burden, at least to me it would be.
It's pretty simple really, its not a deal that we really need to twist with overengineering. Whats going to flow smoother, a straight path or one with a baffle in it? The less angle you can put on that baffle towards straight the better off your going to be plain and simple. I would hedge my bets that in simple hydraulic principles you do not really want your ports playing hide and seek with oil flow. Perhaps an application like that may exist, but I don't want it in my shock.
When I put my sled shock piston together, I went to GV type layout, but mine is on a 30/60/90 layout,in appearence it may resemble a Penske standard. It is not out of square like the GV. My compression feeds are 50% exposed beyond the rebound shim edge. I made sure I had a nice gap. I combined both the PA and RT approach to making sure the potential feed restrictions are minimized The less potential restriction I have on the "feed" the better off I am. There is better design options out there but they are expensive to machine. Most people do not want to spend a $100 on a single piston though.
If your restriction on the feed end is too great,( due to baffle type restriction) your shim deck height is too low, you run the possibility of creating a vacuum in a bad place. You can consider the consequences. Still, it can all be relative to loads placed on the damper. Sometimes though you just can't leave much to chance. I believe Jer has done well with his improvements. Very much in fact.