Problem is, round-robin with 1 guy advancing from a 4-man group is pretty close to effectively being double elimination, except some players will be eliminated after only one loss based on tiebreakers. I think double elimination would be better than the format being used for CSI, and I say that despite not being a big fan of double elim. They could also go WPC-style and do the groups in double-elim as opposed to round robin, and then still do single elim for the final four. Either of these formats would be about the same number of matches overall as what they are doing with the round robin groups, but would be cleaner without the tiebreakers and the meaningless matches.
2 out of 4 rather than 1 out of 4 advancing is closer to double elim. Most groups will have 2 clear advancers except for rare 3 tied I.e. 3x2-1 and 1X0-3