Checking how PCSX 2 has been improving now that its nightly version reached 1.7.2, testing a bunch of games.
This is better than before, but not perfect.
With Frame Buffer Conversion on, like on this image, the whole screen is colored correctly ( according to the software rendered ), however the typical KAL engine artifacts are still present ( much more tame than they used to be, covering 1/4th of the screen in a very distracting way ).