Here comes my second valley map!
This one is easier than the first, you don't get punished for not driving perfectly - although driving smoothly is as rewarding as always. Couple of small tricks on this one but overall a fairly straightforward map.
Driving the dirt at the start smoothly and avoiding the bumps is important if you want to keep your speed throughout the first half. A small trick you can do is drive towards the left side of the water pool, which will give you a bigger bump and allow you to 2-wheel instead of bouncing off the tarmac with a jump, letting you gain some speed. Another trick you can do is a small sideways nosedive at the 2nd jump if you have a lot of speed, this will give you a 'sticky' landing on the downhill with really early grip, giving you a big boost.
The 2nd half of the track is much more tricky. You can gain or lose a lot in the drift, making it really important to nail - which is difficult because of the dramatic speed and angle change. The S shaped turn is an interesting one i think, and I can see a few different lines being possible. I try to go for a wide line at the start of the first turn and exit it tight (spam out as many braketricks as i can just for the little extra angle), giving you a nice angle for the 2nd turn - but I wouldn't be surprised to see better lines.
This ending also makes you decide when to release and when not to release - how to carry as much speed as possible while also having the best angle possible.
I'm satisfied with the author time, and I think a low .7 would be the limit here - maybe a .6 is possible with a perfect run and a lucky waterpool trick, but I'm not too confident about seeing a .6 being done - though maybe the ending line can be improved enough to allow it, only time will tell.
edit: riolu did .60 because his drift cancel is insane