This follows a suggestion from Hayo Baan and subsequent reply by Kirk.
I believe is important to consider a way to synch the catalog as new photographs in the catalog folders are created.
The now obsolete Google "Picasa" software used to monitor the folders and automatically add any new photograph without any noticeable slow down or additional resource use.
I find it very frustrating having to manually add any new photographs to the catalog.
The "Lightroom" way of synchronising would also be good.
In any event a reasonably easy way of synchronising will be better than nothing.