I wouldn't have a problem with buying soap that hasn't reached a full cure, but I've always stored soap for months prior to use, even when I bought store-bought soap. I still have store-bought soap (purchased before I ever started making soap) continuing it's overlong cure in the bathroom cabinet. One of these days, I should donate it to a homeless shelter or something, but it still sits there in the cabinet being ignored.
However, I do know that if I were traveling and didn't have my own soap with me, and bought uncured soap, I would very much want to use it right away. Thankfully I never travel without my own soap anymore.
A couple of times I have given family young soap (not yet cured as long as I like) but at the same time, I gave them well-cured soap with instructions to use it first and that the younger soap needed a longer cure. However, even in my family there are a couple of folks, I would not do that with because listening and retaining such information is not there forte. But I would never do that with an unknown person. Not all people listen well, retain what they hear/read, or even follow safety instructions. And I do know how harsh young soap can be on my hands, so would not want to risk that with another person's body.
The one exception, I suppose is MP soap?