Thats sort of tricky as it would have to save it to the same filename as your set – which could work for mame, but tricky for consoles that have different names, but the same hashes. Even with mame it wont know which romsets you have decided to use.
You can grab your images from emumovies.com – sselphs scraper can use these locally store images and then it just grabs the metadata and doesnt need to download the image.
But in short, I’d just grab it with a scraper – you only have to do it once, and it takes about 5 mins per system.
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