“Adventive” is often used to mean “naturalized non-native”, at least in my region and in its flora. Yeah, a one-off / waif vs. a fully naturalized population isn’t distinguished in iNat’s broad definitions of “wild” vs. “not wild”. Establishing community consensus in these grey areas, especially as outside observers, is often difficult or impossible.
Some related topics, one which I see you’ve weighed in on: https://forum.inaturalist.org/t/add-a-third-option-for-captive-cultivated-question-unknown-or-grey-area/7361 as well as this one which brainstormed building in more nuance https://forum.inaturalist.org/t/establishment-rating-for-plants/5736