Well, a couple of points:
1. Eddie only activated his flanger for certain notes. He didn't play the whole riff of Ain't talking about love with it on, same deal with Unchained. This helps with what to listen for.
2. Personally, I haven't tried to match the phaser or flanger from the actual VH albums, I've used different high quality demos of the gear instead. So no "in the room" clips or clips with excessive plaing etc. Clips with as simple or even static playing as possible and with the amp properly miced up is the ticket. For instance, there is a demo clip on Youtube of a EVH flanger, where the flanger is placed AFTER a distortion pedal and the guy just slams a power chord, makes it that much easier to match the pedal.
3. Something I noticed, not all EVH flangers sound exactly the same with the EVH button engaged. For instance, the time parameter differed from about 0.740 ms to 0.780 ms between different pedals. If this is due to different versions or component tolerances, I don't know. But either way, when somebody posts a EVH flanger preset and time parameter isn't even in that ballpark, then I know it's just way off and not correct. Same with rate, it is roughly 0.450 hz, and I've seen presets with the rate all over the place.