Static had time to hold/block the end of the string because Steady delayed the end of the string. No I don't see where you're going with anything because the game does not imply that you are obligated to use a side step attack after side stepping successfully. It is an option, just like choosing to block, hold, or using a different attack is.
As
@Mr. Wah mentioned earlier, most strings need to be side stepped at the end of them. And most other strings, as I said, need to be looked into in order to learn to know when it's appropriate to side step something successfully.
You are not side stepping Helena's 7PKK on a whim, first strike is i20, second is i16, third is i17. There is literally no time to side step THEN block the end of the string (or follow up with a side step attack) because the KK in 7PKK is frame tight. Competent Helena players will likely always delay follow ups to this string, and Static knows this, which is why he took the risk to side step.
You can side step and side step attack Helena in her 4PPKK string once she reaches the 4PPK because the interval to the mid kick is i20, when 4PP is i16 (second hit).
All I'm really reading from you is that you have a hard time utilizing the side step because you're risking it rather than knowing when to do it.
The side step can be used as a defensive option or an offensive option, depending on the situation you're in and how you intend to use it.