Canoli220 Takes a long time. lets say full set of 16 and 8 bit games takes me almost 2-3hrs. What I been doing is just use a desktop app to do the scraping than coping the roms/images all at once back to the emu PC or pi.
I keep a master set of naked roms (no images), and a set with images that are ready to go for when im building a pi image or a usb for the PC.. If you tell batocera in storage setting to look for roms off any external or the name of the usb that you are using it will reboot and build the file/folder structure on that usb.
From there you can plug that usb into a Pc add the roms and use a Desktop scraper, I will be quicker but its not fast.. there a had full to pick from
Universal-XML-Scraper,, "be sure to update this one"
ARRM (Another Recalbox Roms Manager)