Thanks Bruce. The actual files have the caption or name as their file name...inDesign is set up so that it doesn't include anything after the full stop, which allows the caption to import the name, but not the .jpeg part of the filename.
The CSV route sounds interesting, but I'm not sure it would compete with the current workflow (which means I can't really advocate for affinity use in the work context), can you elaborate a little? At the moment, we can quickly click place the images into our template using the place function.
Another option that could be useful would be integrating affinity with some software I use called notion, which also has a plant library, but not sure if that's dreaming at this stage.