Currently there are only a few different options for tiebreakers when operating a tournament using small group round robin -> single elimination. If challonge allowed for the tournament organizer to select the priority for tiebreakers it would allow each organizer to highlight the measurements they find most important.

Example: In the Ascension 2020 September tournament, two players in the same group finished with 6 game wins, with one player going 1-3 and another going 3-1. The player that went 1-3 won in the head to head and therefore had the tiebreaker ahead of match wins. However, challonge does not seem to allow for match wins to act as a step one tieaker before head to head is applied. Making this modifiable by the TO would be a great step.