Long post but this race was pretty interesting so I want to write about it in greater detail.
To begin with, I knew TK_05's setup was geared toward higher downforce than mine. I also knew that his lap times in clear air were just as fast if not faster than mine - but not enough that he could easily overtake me, and it's difficult to overtake at Mugello without top speed. Therefore, I thought qualifying would be where the race would be decided.
Fortunately, I got a few good quali laps and secured pole, beating my PB in the process. From there, I knew that staying 1st was mostly a matter of not being excessively slow and avoiding mistakes. As expected, TK_05 was faster than me in most of the corners, especially T6 and the section that follows, but as long as I didn't let him too close and consistently got a good run out of the last corner, he could never pass. That even allowed me to be just slightly slower than usual to ensure I made no mistakes and didn't spin out on a kerb.
Which brings us to the pit strategy. If TK_05 was going to get past me, the pits was where it would happen. The problem was, I hadn't practiced enough to know whether I wanted to stay on the same set of tires or switch to new ones, and I had no idea what TK_05 was going to do.
I did notice that my tires were still at 100% even on lap 15, and I wasn't flat-spotting them at all, so keeping the tires and saving 5 seconds in the pits seemed like a good idea. I also reasoned that if TK_05 had practiced pit stops and decided to keep his tires too, doing the same would be my only viable strategy if I wanted to maintain track position.
So I gambled, kept the tires, and quickly realized it was a mistake. I correctly assumed the tires would be at 99% for the second half of the race, but I made the mistake of thinking that the grip difference between 100% and 99% Lotus Exos 125 slicks would be the same as between 100% and 99% GT3 slicks. It wasn't.
I lost about half a second a lap and even more than that initially as I adjusted to the grip (which felt worse because of the topped off fuel tank). TK_05, who did get a new set of tires, was about 5 seconds behind, but that gap didn't seem poised to last for long.
Fortunately for me, TK_05 collided with a backmarker and I never had to find out whether he could punish me for my mistake. In the end I only had to cruise to the finish line and won with a huge margin. It was a fun first half of the race and an educational second half. I look forward to the next one!