"...So....If you have sensitive skin, is it better to use a syndet bar? But my CP soaps have been helping those who have eczema and dry skin...."
I don't think it's true across the board that a syndet bar is automatically the best for sensitive skin. I think each person has to decide that for him/herself. There are many reasons why a person's skin is sensitive, so there are many folks for whom some types of lye soap might be fine, but others who cannot tolerate it.
From what I've read about eczema, there are many triggers for that, including allergy issues. Handcrafted soap with just a few classic ingredients might be just the ticket especially for some eczema sufferers allergic to ingredients in commercial soaps.
Getting back to the OP's question, I track weights too, like Coffeetime. I've found most of my basic soaps lose 8% to 10% of their cut weight by about 4 to 8 weeks. By that time, the bar size is also fairly stable, so I'm pretty comfortable packaging the bars at that point.
Before 4 weeks, the soap is still losing enough weight that I do not feel it is ready for "prime time". Have I used soap before 4 weeks? Sure, lots of times especially when I had less experience (and less soap). But I don't give it away nor would I sell young soap -- it will not last as long, IMO, nor may it lather as well.
I have found that a longer cure time does affect lather quality. For example, I made a mostly lard soap that had a below average lather at 4-6 weeks, but the lather was unexpectedly and dramatically better when I tested it some months later. I'm not too sure a regular person would be in a position to see the difference, however, so I enjoy monitoring these changes but I try to not get too "purist" about it.
To be honest, most of the soapers who get overly concerned about rushing their soap through its cure are newer folks. With enough experience, it's not too tough to have enough batches of soap moving through "the pipeline", so there is time to let the soap cure properly before using it, giving it away, or selling it.