Hi Km,
I don’t have any personal experience with their mattress but with a split queen you would be no more likely to feel a split foundation than with a split king (and all kings are split). With any solid non flexing foundation that has a level surface such as theirs you wouldn’t feel where the foundations come together with or without split latex layers. They will confirm this when you talk with them.
No … it is still foam and would have a very different response from wool and it’s an actual layer in the mattress rather than being quilted to the cover (they also have a wool quilted cover). You can read more about a convoluted layer in post #2 here (in reply to question #4) and in post #2 here.
Phoenix