Hey I had an observation that I thought was interesting on this subject, though I'm not out to trigger anybody - just an observation.
My installation is indeed a Romex 6/3, 60 amp breaker, Tesla V3 charger. After I found this thread, I set the limit on the car to 44 amp, which is 80% of the 55 amps that Romex 6/3 is rated for. Frankly, any difference in charge time between 44 amps and 48 amps has been irrelevant to me.
The observation is that whether this charging system is running 44 amps or running 48 amps as it was before, the 18 foot charging cord supplied by Tesla feels warmer to the touch than the Romex 6/3 does. I've sampled both in several places. Is it not appropriate to take from this observation that the Tesla cord is more of a limiting factor than the house wire? Anyway, I'm not advocating for anything, I just thought it was interesting.