Hi sleeper bob,
Yes … the size, depth, and spacing of the pincores in latex or other surface modifications can be used to create firmer or softer zones in the latex. There is more about zoning in post #11 here and the posts it links to and you can see an example of a zoned latex layer here (with 7 zones in this case).
Typically the section under the shoulder would be softer to “allow” the shoulders to sink in more deeply … not firmer (denser).
Zoning in a mattress can either be beneficial, detrimental, or neutral depending on how well the zoning “matches” your body type and sleeping positions in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences).
Phoenix