Being Jack aware would be a bonus but there are already a multitude of Jack aware EQ plugins. The feature-set of this prettyeq plugin seems aimed specifically at system-wide audio, in other words to adjust the audio on your system to match your daily use preferences, rather than production work. I might never use this sort of EQ (high-pass, lo-pass, 5 peaks) for production work. Maybe for tweaking a final mix... pulseaudio is definitely in need of some nicely integrated audio filters. Jack has many to choose from, but more are always welcome.

Edit: I am not an audio pro and if this EQ is in fact aimed at production, I would love to learn more about its use cases