Yes, that is the link, good find. This was a prototype Curve Tracer based on an a very old commercial DIY design. It evolved over a few years into a very good and much more complete design, credit to a small team. Links are in the blog.
The reason for the overkill Opamp instead of a comparator is simple. I had a large stash of these Opamps from another project and no comparators at the time. It worked and did the job for that project. The original design of the circuit wasn't really mine as you can see in the blog, but that is beside the point. I made sure credit was published where it was due. As we should always do.
I found the url of the original picture. Thanks. Unfortunately it gets to the original location, but doesn't really get you to the Blog post itself.
Never mind, I found this circuit and wanted to alert the user. 'Nough said, thanks for chiming in.