Capitalism’s ideological basis for private property overcomplicates the capitalist worldview. The whole notion of self-ownership is inherently unsound, in that the self is inalienable in the first instance.
Let’s also distance anarchism from all that marxist guff about private vs personal property. There is only property. Likewise there exists no distinction between private and public property; public property is just the private property of the ruling gang. We can also dispense with the red herring of common/collective/communal property since those assume that a property system has been adopted.
Property is an artificial construct, and there there is no default universal agreement on how to . In this respect property systems resemble religion, with everyone being convinced that their God is the one true god. Anarchists are analogous to atheists in this sense, in that they reject any notion of property altogether, along with the need for systems that develop out of it.
Mixing property norms is quite evidently unworkable, but to recognise one system of property to the exclusion of all others, would be to universally enforce a social mechanism for land enclosure that many people may not agree with (ideological certainty notwithstanding). Separation is likewise problematic since this would give rise to distinct social enclaves and mandatory adherence to a property system dependent on territory, a scenario tantamount to statism.
The only reasonable solution is therefore to reject any attempts to impose a property system, and let the decision of whether to respect occupancy & use fall to the individual. The most important free market is the free market in choice. This is why virtually every classical anarchist from Tucker to Kropotkin, has advocated simple respect for occupancy & use as the best means of resolving the ‘property’ issue. The only notable exception is Spooner.
Occupancy & use is entirely predicated on respect. It is dependent on other people respecting your occupancy. In terms of how long you have to abandon a piece of land before there’s a risk that someone else might occupy it… well that falls to their conscience as an individual, which would in turn be influenced by their natural desire to avoid trouble (social cohesion). Therefore, I can quite confidently state:
“Long after you’re done with it.”
If you’re worried that other people might perceive that you’re not occupying or using your property, then you probably aren’t…
Individuals acting independently per their own conscience is just a free market in social acceptability. It really boils down to whether you are prepared to accept a free market in individual choice and acceptance at the expense of abandoning belief in the One True God of Property.