Hi I Need sleep,
Post #2 here talks about the pros and cons of split layering and some of the factors that will make the split more or less noticeable. In general though … I think for most people the benefits outweigh any down side.
Hopefully others will see this and post some of their personal experiences as well.
The split layering will be fine with an adjustable base. If for any reason the layers shift at all (which is unlikely) they are easy to re-adjust as well with a zip cover.
Phoenix