I don't use the plugin myself, but briefly looking at SRDs video on it looks like result.isBlocked() and result.isParried() should be what you're looking for. While the text without the brackets might work sometimes, the function is designed to only be true when the action was actually blocked or parried. Just calling the values like you have in there might make the block popup come up on a miss or evade as well.
edit:
I just tested myself and it appears to work with those functions. Just make sure to turn the 'hide popup' plugin parameter off for both the block plugin and the parry chance plugin, or it will show nothing.
Also, I didn't look into compatibility with this too much, but it seems to work when SRDs plugin loads after mine, I'm not sure if it works in a different order.