I export part of my master catalog to a laptop. I include the image files so I can edit the files at full res. After managing and editing files I import the catalog back into the master catalog. When importing I check to replace metadata, develop settings and negative files. I have been running some tests to be sure all my work is being captured in the master catalog by this process. I find that if I change develop settings or photo ratings this is detected when the file is imported and the data in the master catalog is updated properly. The surprise is that if I delete files or move files among folders in the exported catalog these changes are not detected and these changes are not updated inthe master catalog. It seems bizarre to me that such changes are not detected but I do not see how to get LR to recognize these changes and include them in the catalog update. Without this capability I don't see how to use catalogs to move part of a catalog to another computer for edits and file management and then move back to the master catalog.
There are various reasons why Lightroom works this way, but you'll need use pick flags to indicate photos to be deleted, and other metadata like colours or collections.