...at the cost of interrupting the swing. Which,b y chance, is the most irritating thing that saberist can take in current build - given the (unnecessary, in my opinion) global damage reduction, 99% of times it is better to take damage yet deliver the killing slash, instead of having it interrupted and "just" being stranded with less force pool.
This feature is super useful with purple. It is a slow swing so you can easily get shot during it. But since you have the perk of losing less force per shot you can afford the swingblock. It is better than losing hp/dying compared to swing interruption and getting another try. Ofc you DON'T use it when you are low on fp anyways. But amazingly good when youre low on hp. So swingblock is good when you use other styles too when low hp (and personally I like to use it even with faster styles depending on situation)
This style can be utilized in many different game styles. For example d3 build + purple. You swingblock and get interrupted, the enemy is surely shooting which means you go back to d3 while still sustaining nice fp level thx to defense 3 and purple.
Other times it is useful with any style:
Enemy is pushed down, you go for killing blow, you see some bitch covering him with sniper or blaster. You wanna kill the guy on the floor but not sure of your safety when you swing. With defense 3 you can tank the sniper shot while swingblock and after that do another strike and the guy on the floor is dead and you can reduce the situation from 2v1 to 1v1
I could continue this for even longer but I leave it at that.