>>83078284
A good definition for incel is very different from a set of heuristics to diagnose incels. It's easy to define what gold is in terms of the protons, neutrons, etc. it has, but it is much harder to know if a piece of metal you're holding is actually gold without specialized devices. I think a good definition of "incel" just is a person who has no ability to get unpaid consensual sex with the sex(es) he/she is attracted to me (so not including rape, prostitutes, or sex with men for straight incels).
OP is asking about a heuristic for what will be true about incels. It is sometimes the case you can be an incel who never asked out anyone, but the overwhelming majority of these guys are just normalcattle who are insecure and terrified of talking to women. In my view, unless you're super deformed/disfigured, you'd have to definitely ask out at least several dozen women to know you're an incel. In general, I believe <0.5% of men are incels based on how rare incels are on this board with predominantly virgin men and any sort of place where virginal men come together online, plus all the stats that the number of sexless young men is only ~10-15%, so a tiny fraction of 10-15% would be the rate.
I don't believe disfigured women like disfigured men, but I could be wrong.