I would like to suggest an optional way to select images in the browser: Sticky selection
If you have a lot of images (e.g. a lot of almost-duplicates, which happens a lot with microscopy) you may want to select the "unwanted" ones and put them aside in another folder.
The way the selection works now is that you click on an image (in the browser) and it is selected. If you click another, that is selected instead. If you want multiple selections, that is possible if you hold CTRL while clicking. So far so good.
The problem occurs if you have selected a lot (or few

My suggestion:
To have a toggle in the preferences called "Sticky selection" (with default set to "Default selection"). I imagine it should work as follows: If you click several images in the browser they are selected and stay selected until they are clicked again.
A further refinement by selecting the "sticky selection" could be if when in image preview mode (by clicking "space" in the browser) or in edit mode (double click in the browser) and you press "ctrl-space" then the image is selected (or unselected) in the underlying browser, and when you return from the preview window, the files are still selected for further processing, such as moving them to another folder etc.
I hope you will consider this - it would make my (and maybe also other's) life much easier - and my colleagues would not hear me swearing so often

Thanks
Claus