Session import doesn't work when capture folder is empty

My usual way of working is to import my image of a project into a session, selecting and trashing them, sometimes until the capture folder is empty.
The selected images I post-process in the session and export them as a tiff file in the output folder. At a certain moment in time I decide to import the session into a specific catalogue. If the capture folder is empty, no images are imported, so at least 1 image has to stay in the capture folder. I find this annoying.
Maarten