I want to point out that in law, the word “necessity” is defined as being beyond or outside law. So whenever someone claims or implies necessity, I naturally assume they feel that laws (as they apply to rights, contracts, norms) do not apply.
Hence when our friends of the left talk about the necessity of doing this or that, what they are really saying is that the laws don’t apply to the situations they are concerned with.
What appears to be an ad hoc philosophy wrt property, is in fact ad hoc, although they will tell you their perception of necessity (the very thing which makes it ad hoc) is systematically derived.
Necessity is not meant to be used as a systematic excuse, but as we can see in this discussion, and many others, every situation is a lifeboat, and so, every situation is outside the law.
An emphasis on context or situation is not a reduction to lifeboat scenarios. Lifeboat scenarios are only one kind of situation. The fact that one refuses to adopt an absolute a priori rule does not mean that one has no standard. The problem is that the very nature of an absolute apriori rule cannot account for particulars/details.
You (and others) use “context or situation” to demonstrate necessity. You have to, because there is no way to establish a libertarian-compatible rule about preferences and attitudes.
You treat every situation as a lifeboat however. They are all based on ad hoc justifications of “necessity” because you cannot make a rule argument for them, without creating a rule of rights violation, and you know that is not going to withstand any scrutiny.
If your rule is not consistent, it is not a “standard”. It is ad hoc. Which was my original point. You make up rules as you need them, and change them as they suit you and your perception of circumstances.