Thanks for your input Glenn, it uploads all additional images to the /images/ folder and saves the image name to the product as an additional product field in db just like the main product image. Could even add these image names to db via EasyPopulate just like main image.

Like the main image it will over-ride and delete image name from db but not delete image from /images/ folder.

I haven't altered any code for example on the product_info page, so all the images uploaded with the ZEN additional image name structure will be linked to the main image as normal.

Not sure how it would handle existing additional images for they are only in /images/ folder and the names are not stored in the db. (I think, still exploring how zen additional images work)

As of right now (9) additional images is all I really need and haven't put much thought into allowing for more!