Hi EdinMass,
That’s a good question, and as Sweet Dreams pointed out (thanks!), you’re describing a zoned mattress system.
Various zoning systems can be very useful and worth considering for people who have more challenging circumstances or sensitivities, body types that are more difficult to “match” to a mattress, more complex medical issues, or who have a history of having more difficulty in finding a mattress that works well for them. There is more about zoning in this article and in post #11 here. You may also want to read post #2 here and post #7 here (latex monozone unique properties).
Zoning can add to the complexity of selecting a mattress, so I strongly encourage you to find a knowledgeable manufacturer or retailer with experience specifically with zoned systems if you are considering such a route.
Phoenix