I like this calldown. Villian is so polarized and we block lots of his value hands. I think Villian will not valuebetting for example A9ss with this sizing on river. Maybe I prefer caldown with something like K6hh or some thing like that because we don´t block any of his bluffs - 65s, 54s, QJ, Q9 and lots of his 9x hands. The question is how frequently will opponents bluffs with this sizings on turn and river...

Another thought I just got is if we can fold the turn and I think we can if we design a good c/c range for the flop which includes a lot better c/c-twice hands

I think 67 of hearts lives a lot off of improvements on the turn or check behinds from villain

Another thought is that I almost think that if villain were to bluff this river, which I think is actually also quite favorable for OUR range (think Ax flushdraw, AT, A8, A7) and in a way kind of doesn't connect with what he is repping at all,...
he would probably overbet (if he is thinking/good) which makes this size sort of betsize-telly and might be skewed towards valuebets
...just a thought but in general I dont think the calldown is super terrible