Yes, it is currently free.
Wavegrove has offered some plugins for free or on a “pay what you want” basis at times, but Vastaus itself is typically a paid plugin (usually priced modestly). To get it legally: wavegrove vastaus plugin free download
You can download the latest version of Vastaus for free from the following official platforms: Yes, it is currently free
: Allows for parallel processing to blend the original signal with the smoothed output. Why Use Wavegrove Vastaus? Why Use Wavegrove Vastaus
I should also ask for clarification if the name is correct, as it's likely a mistake. Maybe they meant a different plugin. Providing alternative steps, like searching on the official website of a company like Waves Audio, could help.
Essential for parallel processing, allowing you to blend the processed smooth signal with the original transient-heavy audio.