Amazing videos. I've been thinking about it since you posted.
I can't imagine how you kept the handle bar straight at 140mph.
First run I ever made was back in 2017 on my old pro twins bike with a 5 speed. I was heading down the track looking at these black marks which were at a low angle to my direction and I said to myself, I'm going to drop my front wheel in a groove, get a tank slapper and die. Well I survived that first run and then I walked the track that evening. Seems the cars lay rubber on the dry mud. What looks like black grooves are actually simply black rubber marks on the dry mud. There are no grooves for the front tire to slip into.
That first run was even more interesting. I tried to get my "rookie" weekend waived and get a full license based on my years as AMA pro roadracer, etc. To this end, tech inspection put a sticker on my bike that forced the race director to follow me on my run and critique it. He was less than pleased, and found some nit to deny. Why try for this? Because rookies can't set records, and I thought I could (as it is I got within 1 MPH of setting the record that weekend, and did it next event.)
What was even weirder was as I was making the run, I was riding a bike I hadn't ridden in anger in over 24 years. In that time I broke my left ankle. Well, I missed the shift into 5th. I then took my whole leg and giving it a strong upward jerk missed the shift into 5th a second time. All this flappage, then started to induce a weave into the clipons. This going on while I was still ignorant about the black marks had me convinced, this is it. So I left the bike in 4th and ran 115 that first run. When the race director came over to me when I stopped to tell me I was too slow turning out, no waive of rookie rules. I was literally stammering, "hamma hamma hamma", scared sh*tless. At that point I could care less about the license. And all this was for 115. By the time the 2017 season was over, 140 felt like nothing.