That product-page plugin you're looking for could be based on this (https://mark-rolich.github.io/Magnifier.js/). I "know" there's a prepackaged version out there somewhere but can't find it quickly.

The image-zoom provided by IH5 (to be removed in the v5.2.0) isn't working on the by-category products' listing since you're (apparently) using a product's medium-sized images for that display and the image-zoom is applied only to small images.