While developing the various features that make up disaggregated storage, we added the configuration options in a relatively ad-hoc way. This resulted in some awkward options – for example there's a separate config for which block manager to use, which should be a WT-internal decision.

Ideally, the configuration would be reduced to two elements: (1) loading a page and log extension in wiredtiger_open, and (2) the type=layered config when creating a table.