Of course it's ok to turn your feet to the side. We wouldn't call that a monkey vault per se, but it's progression definitely. Don't worry about how quick you're progressing, kong vaults/monkey vaults have given many a traceur issues. Don't expect to get it on day 1, don't expect to get it on day 150, it will come to you whenever it feels like it

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The trick for me was to go over the object as if you were going to land in all fours, in a "quadrupedal position." So get to your object and check out the other side so you
know what's there. Doing that helps keep your mind off whats over there while you're airborne and lets you focus on the actual feeling of the movement. If you're at the point where you clear your obstacle with your feet out to the side you'll be ready to monkey. The higher you can get your hips and the more horizontal your torso, the better this will go for you. The "landing on all fours" schtick is literal, try it.