Saving as SVGs with embedded images on different artboards

I have an AI file with 6 artboards, each artboard is a different shape and size to the last and all contain the same jpg image in them. I want to save each artboard as an SVG with the jpg on that arboard embeded in it.

When I go to File>Save as (I cannot use export for this job as the developers have given very specific settings I need to add which I can only do via the save as route), then select SVG and tick the 'use artboards' option I usually get 6 different sized SVG files as each artboard is a different size... however now all seem to be the same size (2.5mb) which is about 10x too big...

Initially the jpgs that were embeded into the file where waaaaay too big, so I have unembeded, compressed in photoshop and readded them (added 1 to the first artboard, then copied and pasted this to the other 6 artboards, each artboard has its own layer in the layers panel, then embedded all the images).

However I think the step above (by embedding after copying and pasting) has meant the 6 images are linked to each other somehow and that the image data for all artboards is being included in each SVG (I may be, and almost certainly am wrong though!)

Reason I think I may actually be right is that if I go to the links panel, select all 6 images, 'relink' to the original jpg 1 at a time and then follow the save as steps above the files are 240kb (ish).

Is there a way to quickly fix each file/unlink the images from each other so I can save all the SVGs (I have 740 files x 6 SVGs to work though!) to solve the issue without haveing to relink all 6 images as I had to do above please?

I have included the larger (pre relink) and smaller (post relink) SVG for comparison if needed to help diagnose the issue (as you can see the large version is 10x larger than the small but looks the same), I'm hoping this is something obvious?

Thanks all