If I may be indulged for a bit of a rant, Ancaps are basically flat earthers. Similar to flerfs they are not there for the stated reason. A flerf does not care about the shape of the earth. Their main motivation is a religious one and the shape of the earth is just some front end reasoning for the rest of their theology. Ancaps are not there because they care about economics or freedom; that is just there as academic cover for their bad political motivations.
Similar to a flerf they lash out when you point out a flaw in their thinking. If they did care about economics from a truth perspective that would be welcomed. In the natural sciences we have ruled out bad ideas (flat earth) or found that existing ones were incomplete (newton to general relativity). Pointing out that the NAP is not that end all be all logically or citing any historical precedent is not welcomed.
Even accepting some of their axioms as truth leads to bad outcomes. If I was in ancapistan and successful why would I risk a new comer bringing my trade fiefdom down when I can sabotage them. Or if profit is my motive, then why would I care about injust NAP violations that don't directly hurt my profit (further why not join the aggressors in a share of the spoils).
Ancaps (and Austrian Econ types) are to economics what flat earth is to physics.