Hello Scott,
You can have multiple assets of the same type in the single chunk (dense point clouds, mesh models, tiled models, depth maps sets, orthomosaics and DEMs). To achieve that for orthomosaic, for example, you should right-click on the orthomosaic label in the chunk's contents of the Workspace pane and uncheck "Set as Default" option in the context menu, after that generate a new orthomosaic and you will have two orthomosaic assets in the same chunk.
To switch between them double-click on the corresponding asset label in the Workspace pane or use right-click -> Set as Default concept.