Oddly enough, that's why I like the idea of being able to let those self-selected experts get attention on the AT-trial mismatch question (via such a metric and followup surveys). If such a signal does appear among even such an experience group, one can be fairly certain there's a real mismatch between a particular AT and a given trial, not just a phantom signal from semi-casual players who haven't yet found a tactic to enjoy their character's possible roles in that trial. It does require/assume there would be a large enough sample of devoted "not in it for the Merits" players to show anything on this point. And I wouldn't propose using that self-selected experts/"trial lovers" metric as the only one. For example, metrics for alt-heavy Incarnate players could be quite useful...though they'd probably already seen those (I fit there somewhere). My curiosity led me to ponder a metric they may not have even considered.
Sometimes yes, sometimes no. For example, there was definitely a deficit in masterminds, and that was because most players, even the power gamers, were upset about their (lack of) ability in the iTrials, with good reason (as I noted, the purple patch is explicitly intended to "punish" players that venture above +5, where the curve gets radically steeper, but Masterminds with their -2 and -1 pets are compelled to operate in that regime). There was also a deficit of VEATs (at least by my reckoning) but I don't think that was because VEATs were problematic, rather it was because a higher percentage of players were interested in developing other characters besides VEATs earlier. In other words, I think far less players were likely to "prioritize" VEATs in iTrials simply because VEATs were newer, and more players were more likely to be attached to and want to develop other characters first. If the game had lasted longer, I believe they would have eventually shown up in greater numbers more in line with their population overall.
Another factor to consider is that on most servers the iTrial runners were divided into two basic groups: the organizers and the followers. Pick up iTrials happened, but a large percentage were organized efforts driven by the same smaller group of players that gathered members from a larger pool of "me too" players. These two groups were in it for different reasons statistically. An assumption that might not hold is the assumption that there were two main reasons for a player to run an iTrial: they enjoyed running the content for the pure gameplay, or they did it just for the rewards, or both. But there was a third reason: they may have run them because they liked to organize and run large scale content of any kind.
Trust me: almost nobody actually liked herding cats in a Hamidon trial (especially pre-I9). That element of "gameplay" is only enjoyable to a masochistic few. But there were people who enjoyed on a meta level organizing and leading the raids, and did it for the satisfaction of doing so.
One more statistics-skewing (related) issue was badge hunting. I ran a lot of iTrials that were explicitly intended to hunt badges, without regard to any other rewards. I know a lot of players that helped out in those trials for no other reason but to help out other players. They had enough incarnate rewards to choke Jurassik to death and had better content options to run, but they enjoyed helping other players acquire those specific rewards. On Triumph, badge runs might have been more than 10% of all iTrials ever run (I wrote a definitive Obliteration guide based on the work we did to first snag that badge on Triumph). If I was doing something else and someone asked if I wanted in on an iTrial, sometimes I did and sometimes I didn't. But if someone specifically asked me to help them on an iTrial badge run, I would almost invariably drop what I was doing (if solo) to do so.
