You might be holding on to 'outdated' definitions. Here they are as they stand now:
Troll: Disagrees with individual or community. No/little/inadequate attempt to soothe egos potentially damaged.
Toxic: Disagrees and presents an alternative that is dangerous to the ego of the individual or community.
This comment is now considered "trolling" and I, a "troll".
Edit: An especially correct "troll" (as above) can be promoted to "toxic" without presenting an alternative if the disagreement is particularly damaging to the ego of individual or community.
It's not that they disagree or "hold an unpopular opinion", it's how they express said opinion.
Some people can champion unpopular opinions in insightful and interesting manners. Others are kneejerk contrarians and collect opinions that are likely to get themselves the negative attention they seek.
Troll: Disagrees with individual or community. No/little/inadequate attempt to soothe egos potentially damaged.
Toxic: Disagrees and presents an alternative that is dangerous to the ego of the individual or community.
This comment is now considered "trolling" and I, a "troll".
Edit: An especially correct "troll" (as above) can be promoted to "toxic" without presenting an alternative if the disagreement is particularly damaging to the ego of individual or community.