Could you have it set up with a toggle that would be "off" for the lighter-weight standard images, and then you could toggle it "on" to add a lightbox or a link, with the cost of making the element a little heavier? To me, the lightbox is a bigger deal than the link, as a link can easily be added by right-clicking "wrap in a link".

The whole point was to streamline the widget and reduce code output.. It’s easy to fix by using a wrapper link.

I agree