Somewhat tangential to the topic of Rafa in absolutes, but i was personally always kinda disappointed Caio Tera never tried his hand at the ADCC.
I suppose he figured that, since the lowest weight class offered was technically 1 or 2 weight classes above his usual competition weight, it didn't make cents to risk his brand to try to prove a point where most 'casuals' would not appreciate (or even be aware of) in case of successes nor excuse in case of failures. As someone who simply appreciates action and high level displays in contest though i'll always consider it a missed opportunity.
It's interesting to note that he's won no gi worlds 10 times, 10 years strait. To put that in perspective even guys like Felipe Pena or Yuri Simoes have only medaled one or two years (times two if you count double golds). It was appreciating that fact that really made me starting thinking 'what if', and it's interesting how focused he was on showing up every year, even though he started life as more or less a pretty much exclusively gi oriented guy. May hap not coincidentally, Bruno Malfacini has also not opted to try the ADCC (or No Gi worlds either, for that matter).
Perhaps it was his way of saying, 'i could do it'.