I'm not crit expert, but for me it was 4 pretty tight corners. Turn one was the widest coming downhill at good speeds.

Turn 2 & 3 were the hardest (Turn 2 is the biggest spike each lap (90° climbing turn - big ring power climb)

Turn 2 was either a tight inside corner at the curb or a wider momentum-carrying turn on the outside where you risked hitting the large grate just off the corner. There were at least two - but I think three - folks that overcooked that corner and got spat out of the pack.

Turn three wasn't quite as tight, but it certainly felt like the inside you could lean into the telephone pole that was up against the curb with your face if you tried.

Turn four was usually the easiest because it had the least momentum before shooting back down the gradual grade to the start finish and the fast turn one again.

After the road race on Saturday and TT Sunday morning, it took me ~20 minutes of the race just to get loose and it felt like I was just hanging on. I'm assuming that the 17-20 minute was two laps I did on the front-ish

I came up the inside around lap 20ish with a slow down in momentum, but didn't have to pedal to get there. I thought I'd be toting up a teammate we had for the GC, but I got there and saw him 2/3 of the way back in the pack again and let the pack move around me.

I probably should/could have done a lot more but simply don't have a lot of crit experience.