I sometimes do that too, especially with larger images. It would be nice to have it both above and below the image. Maybe there could also be keyboard shortcuts for zooming?

Alternatively, just get rid of the clickthrough and make zooming work like on the forums - click to zoom, ctrl+click to unzoom. Clicking through isn't useful, in my opinion. Plus just about every browser these days lets you view images on their own very easily, there isn't much need to have a dedicated feature for it on a website.

I'm currently searching for features to improve in PJv4. I can't promise that this will get in as there are much more important and bigger projects on our todo list, but I'll make sure it gets passed on to the developer!