First, there are a number of hero planners that have all that data already in spreadsheet form, so you could get the data relatively painlessly. You’ll probably have to find one that has the source data exposed or be willing to contact the people that own the spreadsheets.
Second, It would be interesting as a data point, but I doubt it would be awfully useful since the effect of the special is very dependent on team composition. An elemental debuff could be less useful that an all-defense debuff for a rainbow team, but could be much more important in a color stack that takes advantage of that debuff. And even then the effect would be subjective.
I find just looking at Pois’ sheets is the best way to compare.