Of course, it's super cool! Instant blocking things is very importand for haku! Similary, Instant Block allows you to punish moves that are normaly too far out of range, or unpunishable
for example, Ragna's 5C>2D is a true blockstring. with normal blocking, some blockstrings won't let you do any D move to punish, But the Instant Block is a problem solver!
try to learn some basic combos like, 2A>6A>5A>3C or jB>5A>guren>2A>3C if you execute some of those you'll be able to do more
it depends on the starter of the combo and how much stars you use for it, for more info check out the combo thread!