Ahn'Qiraj Circuit Reverse: Gold

Also just managed Reverse Gold with 68.1s
I did Skyward Ascent (SA) whenever I needed to go upwards (see points listed below), otherwise spam Surge Forward (SF) whenever you get a charge, but be careful to not run out completely right before the flat parts. Aim for the edge of the curve of the rings and stay close to the ground whenever possible to recharge vigor, you really have to fly a quite perfect line here.

SA points:
2x right at the beginning (start "running" while pointing the camera upwards, hit it twice and then aim down into the first ring)
1x right after going through the ring at the lowest point of the first steep drop, on which you should NOT use your vigor while going down (right before the insect tunnel - make sure you're already pointed upwards when using SA to get the most out of it)
1x after the insect tunnel (as you're going up the stairs to those standing purple stones - if you don't have a vigor to speed through the stones, start over)
1x after the last sharp left corner (as you have to go up to a high ring once more before the last drop & final stretch)

Race Start:
Immediately hit 2, 2, 1.
Use 1 until the valley, then use 2, 1 to rise and barrel into the insect tunnel very fast.
After the insect tunnel, wait until you turn right into the ring before hitting 2 to climb the stairs.

Keep your corners tight and use vigor on cooldown after that.

Race End
Hit Skyward Ascent at the rise towards the end of the race, but wait until you are aimed downwards at the next ring before following it up with Surge Forward.
You should have enough vigor for one more Surge Forward to get you towards the finish line, maybe a second just before you go through the final ring.

follow mjmeowy's advice, but in for me it works when I save vigor in the beginning, only start spending them after the stair, burn like it like no tomorrow, 68.9s, 0.1s under.