I also looked at these options early on, and I have a simple engineering question: what about the concept of using more power on that controlled (switched) loop than it was designed for? I haven't measured the existing light but my best guess is that it pulls about 50-75mA at 12V (resistor limiting methods waste power - the LED probably is 3V @ 50mA).
If you advocate a DIY solution and believe that the Tesla drive circuit likely easily supports 200mA or so per channel, then 'have at it'!
But a supported product takes an additional risk which I was not happy to take - that my design (some of these draw upwards of 250mA) would physically damage the internal drive device and I would be liable for that. I tried fruitlessly to get internal Tesla data about the max current that each light circuit might take, and have had no luck with any of my requests.
So, I fully believe the car can support these add-ons well up into the 3W range (12V @ 300+mA) but I'd not bet my company on it.
David