Most large sailboats don't have a drain plug because the cockpit drains are designed to be above the water line and are open all the time. As far as Novelman's drain plugs go, I'd be interested to know if his drain hoses cross or not. If they do, he does some pretty serious sailing in his L25 (crossings to Catalina Island if I recall) and that illustrates a design limitation of the boat, in my opinion.
There just isn't that much vertical distance between where the drains exit the hull and level of the cockpit drains (perhaps a foot if I recall correctly). The drains are also fairly forward on the boat. That makes it easy to bury the leeward drain when close hauled.
To be frank, I was never happy with my drains, but that was more that when I replaced the pot metal sink drains (I am not kidding) with forespar marleron drains and it turned out the the drains nice looking 2 inch grate was mostly false and the grates were easily blocked by leaves the diameter of a quarter. Pretty darn disappointing for the price, but I bought them because they looked fine on the web site and I didn't want to enlarge the holes in the floor. I pulled up to my boat July 4th weekend once and the cockpit was filled to the top of the lazarette. Water had luckily exited under the hatch and out the hole in the stern so my boat didn't do something more severe...like sink at the mooring. If I had kept my L25 I would have mounted some drains in the back wall of the cockpit in the two depressions in the floor and straight out the back. My theory being that the vertical drains would be much less likely to be blocked by debris.