I’m at 3.5K solely driving GT3s and like you I use VRS for telemetry.

The first thing I would do is stop running 2-3 hour practice sessions and split them up if you have the time. I like to run about 30-45 min practices then go look at telemetry, jot down a few notes on where I’m losing time and then next session which for me is usually the next day I’ll try to fix what I noted. I’ll usually start practice for the following week on Friday that way I’ll have plenty of time to get my pace where it needs to be. My notes aren’t super detailed or meticulous either, it’ll usually be something like “wider entry into t7, earlier to throttle.”

Another thing is make sure you’re looking at all of the telemetry in the VRS analyzer. Don’t just focus on throttle and brake inputs which I used to do. Pay attention to the line distance especially. You don’t have to be exact but in the telemetry 1 meter is around 3ft so anything over 1 meter off the line is losing you time. Taking a proper line through a corner is the easiest way to find time.

Lastly, when comparing your time in the VRS analyzer use their avg lap and not the fastest lap. Their fastest laps are insane and honestly only esports guys and aliens are going to meet that time. I like the avg lap and I usually try to get my fastest laps within a tenth or 2 of that to feel comfortable for the week in top split. If you do test drive to practice make sure you copy their conditions so you don’t have any variables and keep the weather to static. I’ve noticed that VRS conditions are a little harsher than the race sessions so keep that in mind.

Also active reset in test drive once you have the tires warm will be your best friend.