Not into poly but that is some nice art from Kishi Torajirou as usual.
Polyamory isn't like futa or age gap, it's not really something to be "into" it's just... like... a thing that exists sometimes
Plenty of things exist in reality, that does not mean you have to be into them in fiction. And in fiction specifically, stories with poly often come off feeling unbalanced with a "losing" side clearly left out. And lo and behold, author's twitter seems to indicate that this is yet another one of those cases. Thus personally speaking, I have found such stories unsatisfying.
So yes it is something you can be into, or as is the case, not into.