Interesting Andy. I'm not seeking to argue with you, as your experience is clearly your experience, but let me share my experience.
I've got a '06 B7 RS4, and starting out to replace the side and DRL bulbs as an experienced electrical/electronic guy, i indeed 'calculated' the resistor value to replicate current draw of the existing bulbs. And by that logic the DRL bypass resistor is indeed in the 6-10 ohm range. However, the heat dissipation is huge. I didn't want to mount the resistors externally with all the hassle that generates. I wanted low enough dissipation that i could mount the 2 resistors INSIDE the removable 'cap' on the headlight assembly.
So, i ran a series of tests and eventually concluded on 24 ohm (50W) for the DRL and 68 ohm (25W) for the side. I have 100% tested and have no bulb failure indications per your tiresmoke article under any set of conditions. (On or off or DRL on the xenons coming on automatically etc etc). Also it's not breached the sealing on the cap, doesn't run hot and is seriously neat. Pix on request.