I guess I will be the black sheep. I had one of those on my old R6 for 5 years, in the exact setup you described, with the racing cap that was pre drilled for safety wire. The inherit design of the drain itself would not let it leak, and the cap having an o ring on it is just double insurance. I have countless miles on the Fumoto drain valves on my current and past cars/trucks (I understand they are different brands and different designs). Really, my only gripe with the drain plug was that you needed that little tool to drain the oil. I am a huge fan of their brake bleeders as well...but that's a different topic.
Just to be devil's advocate, there's nothing explicitly stating in the rider's manual that those types of plugs are not allowed. Like I said, I had that valve for the 5 years I had the bike and not once had any problem at any WERA or any track day org weekend. When properly wired, the cap cannot loosen, therefore the plug itself cannot loosen. Wired is wired.
All that said, I've quickly become a fan of Pro-Bolt's pre drilled drain plugs with the magnetic tip, especially once I got away from the mentality that the oil must be hot when you change it. That was the real benefit to the Stalhbus drain valve, not burning your finger tips. But now that I only change the oil when it's cold or just lukewarm, it's not a problem, and honestly I'd rather have the magnetic plug to catch any possible debris.
If I had it my way, I would not even allow the use of a spring clip for the drain plug (WERA style), regardless of the type of drain plug used.