Hi @kieran_holden Welcome to the community
You can’t replace background images using Symbol overrides just now, but you can still do this using overrides and standard images. (Which is better anyway as you can add alt-text and have responsive variants of your image).
You can set the image width to 100%, the height to 100vh, and use the new
object-fit property set to cover, and Voila. Which is French for “Voila”.
I did a video for you (3 minutes) where I placed all the content into one section (you can of course do multiple ones) and added the overrides so you could see how it was done.
I hope this is helpful and answers your question, please let me know!