The way I did it, I don't count the seed leaf node. so it would look like this, and I would cut at the purple line and no I wouldn't do it yet. And that would be the 4th node almost fully open, so if you count the lower three as
ready, but 4 as
not quite, then 5 and 6 as
just showing, wait for 6 (whichever way you count it) to open fully.
View attachment 4269075
Even counting the seed-leaf node, that would be 5 almost open, and by the time the 6th is open you should see some definition on those sprouts. I would definitely not cut now, but I
would decide which node to keep and watch those sprouts. the leaf size on the very first node are what I would look for in the keeper sprouts BEFORE topping. They have to be able to support themselves, with basically 2 fan leaves once you do the dirty. Also look at those 2 keeper fan leaves. That might also help you decide which node to keep.
That said, I would decide which shoots to keep because you can start pruning away sprouts you don't need as soon as they are big enough to get at. Leave all the fan leaves, unless they are shading your keepers.
Looks like a damn fine plant though!