It's corny not to write your heresy in the comments and that's it. Just think to whom and what are you trying to prove and why should the person on the other end of the network cable not care about all this? Usually you try to prove your point of view to a stranger, often also an aggressive person.
First, you should always keep in mind the fairly obvious thing: what you say or do will never merit absolute approval. The Internet, due to its large number of users and an atmosphere of anonymity or impunity, is an excellent platform for expressing discontent, and, as a rule, in a rude manner. In this regard, I believe, you should have two things: the ability to distinguish slander from criticism and the ability to ignore slander. I think there shouldn't be any problems with the first one. But not everyone can unlearn not to take offense at insults.
As for the expression of an opinion, it is advisable to keep in mind the framework within which it will have the right to exist. Of course, everyone can express their opinion, but this does not mean at all that the right becomes an obligation and you need to shove your expert opinion everywhere. If you cannot count on any validity of your verdict (if any), then it is better to refrain from enjoying the benefits of free speech on the Internet. The most glaring example of abuse is political news discussions. Almost everyone knows nothing, information is obtained exclusively from the media with a certain ideological bias, but everyone can write a whole book about the current situation in Ukraine.
It depends on what kind of dispute we are talking about. If this is a dispute for the sake of a dispute or a dispute in order to show how cool / smart / and generally the most common person on earth is, then the dispute is meaningless. If a dispute is understood as a common desire for the parties to come to the truth, then why not. In any case, we are all different and it is not worth it to be offended that someone there "minus" you and offended you. People who in a dispute become personal, move arrows and use an abnormal little finger do not stand.
1 cut the truth-uterus, let them minus.
2 It doesn't always help, but there are "3 sieves" that are sometimes attributed to Socrates: if it is not exactly true, or not something good, or not necessarily, you don't have to.