I'm no pro by any stretch of the imagination, but, you description, sounds like you are going about things quite well and have a good game plan.
While proper fitting (for you) equipment can make a difference, IMO... Good technique is more important.
The equipment changes I've made recently were just "eyeballed" recommendations from my instructor. She observed my swings on video and looked at my shafts, then she commented that they're not the best suited for my swing speed and transition move, and made some general recommendations. I tried a couple different driver shafts at the end of a lesson, and found something similar/comparable used on ebay to try as an experiment.
As you suggest, I'm planning to schedule a true fitting for early 2020 and see if I can optimize my equipment (for a reasonable cost). Perhaps I'll learn that I don't need to make a change, which I would prefer, as I like to spend my money on the golf course and lessons, and not on equipment.
Right now, I still believe that the biggest issue for me is that my swing is work in progress, so I'm not expecting any magic bullet. But I'm getting to a point where I think better fitted equipment can make a noticeable difference.
My lessons are indoors with a GCQ launch monitor, but I'm not really focusing on club/ball data, more so on what feels/technique my instructor is getting me to work on. She does point out when there is a change in club/ball data from what we are working on so the data is nice for affirming progress. For example, after recent change in my backswing and transition move, my 7-iron swing speed went up from ~78 to ~90 mph.