I don't want to give too precise of a time line, because I'm sure others are better at it, buuuut if you just got your bp 4 days ago, you should give it time to get used to its enclosure and not hold it or even bother it unless completely necessary.

Also, is him being pearched closer to a heat lamp. This might be a sign that the temps are off.

In regards to your actual question about S-ing, generally the "im about to strike" S is a very tight one, where as the normal is a bit less compact. There are always exceptions to the rules, and as you get to know your new bp, you will pick them up.

Stress + sudden movements = ouchies