Young people that fall into reactionary thoughts because they're disillusioned by capitalism might still be brought over to some extent

These people usually aren't actually fascists, at least in my understanding.

They get duped by fallacious narratives and impressive video edits and some edgelord takes online but they aren't dedicated to serious political efforts to understand and advance fascism. They are just misguided larpers who need to have someone shake a bit of sense into them.

The next level up from that is when these people get recruited into fascist groups or they fall in with fascistic street gangs. It's common for a person who is born into fascism to reach this level and those people who grew up indoctrinated and with the full weight of family/social conformity pushing them to be a fascist, I think, are still very much capable of redemption. It's also not out of the realms of possibility for a person in this situation whose political development hasn't reached its full maturity to break free from this too. Some people grow up rough and fall in with the wrong crowd - sometimes by bad luck that rough crowd happens to be fascistic (or the group develops into fascistic tendencies and it carries its members along with it.)

Once you're past that level though, you're looking at actual, legitimate, devoted fascists. Ones who are ideologically aligned to fascism and who enact fascism in their lives, whether through violence, politics, or being a crypto who is just waiting for the right season in the political landscape where they can finally bloom (think modern-day Italy under Georgia Meloni).

With these people I think the best position is to consider them a lost cause unless an individual genuinely proves to be otherwise but you should maintain a high level of skepticism and watch closely - you want to understand how they developed out of fascism, how long that took, and you want to carefully observe their development in politics and values going forward.

Imo a good rule of thumb is however long a person has identified as a reactionary (whatever it is - TERF, MRA, fascist etc.) is roughly how long it's going to take for them to truly shake off their former politics, assuming that they actually commit to the change.