2

Idea:
After placing the reference image on the canvas, have some buttons somewhere where you could swap image with all the images inside the reference folder where you got the initial image by using it's relative path.
Basically a simple image viewer on your browser.

Case
When I am making a illustration I make like a mood board on the canvas, but I only use one image or two at a time as a reference on the side while I draw.
Swapping would not force me to go change application to choose the correct image or constantly alter my zoom to find my correct reference image.