The way I’ve been using (and heard it being used) is more about the act. For example: “Nakiki-usyoso ka pa dyan! Pumasok ka na nga!” (“You’re even spectating over therel! Come right back in, you!”)

There’s another word, usisa, which I would characterize as more like “to investigate, to look into” but is also akin to usyoso in a way I just can’t put my finger on. I think it got conflated with usyoso as the colloquial uzi (from usisero/a, “someone who is overly-curious”) took hold (example: "Uy! Wag ka ngang uzi! Kita mo na ngang nag-aamok na yang si Mang Torio eh. Pumasok ka na dito, bago ka pa madamay dyan!" [“Hey! Stop being an onlooker! You already see Mang Torio running amok. Come back inside before you get involved.”])

I’d use neither to refer to the feeling of “wanting to find out about someone I’m spectating on” though. Personally, I’d just use something like na-intriga (“got intrigued/curious”). For example: “Na-intriga ako dun sa nabasa kong blog kagabi. Ano na kayang nangyari sa kanya. Huling post nya 2020 pa, tapos depressing pa yung post.” (“I’m curious about the blog I read last night. I wonder what happened to them. Their last post was on 2020, and the post itself was depressing.”)

Who knows, maybe the dictionary is wrong, but I guess it wouldn’t be wrong to extend the meaning of usyoso. Yay for language evolution