Creating rated thematic tournament - Opening based tournament

Not able to create a thematic tournament. Once I remove the FEN value and then check the rated button, it is creating a rated tournament . But when I do with some opening, it is creating casual tournament

Custom thematic tournaments are casual only, because there is no guarantee the theme opening is balanced. If it is unbalanced, then it would cause a form of sandbagging, i.e. compromise the integrity of ratings.

I agree, but lichess can provide the basic openings list which are part of the ECO and players can use the one opening from the list of available openings. It would be better than have a random position tournament which if not from ECO list doesn't help/appeal the greater community of chess players.

I hope we get the ECO list back and therefore rated thematic tournaments.
None ECO openings unrated, fine for me.

Thanks!

Agree, that ECO list-thematic tournaments should be rated, at least optional! Whoever thinks there is a bias doesn´t need to participate, so why not allow?