I have (among others) an Elite DVL-90 and find its YC output superior to any CVBS to xxx conversion point in my whole system. (FYR: on the contrary, the CLD-925's YC out is not nearly as good and I don't suggest using it ever.)
Anyway, I go out of the Pioneer with YC, into a Pansonic BD Recorder and from there in 1080p HDMI through the receiver (no changes here) to a Panasonic TH50PZ800. With good LaserDiscs the picture is good, with bad LDs, the picture makes you cry, as you'd expect from a 50" screen watched from 2.8 meters away.
If its a LaserVision discs, I leave the Audio with it, anything else goes out coaxial through a B & K DT-1 RF demodulator.
Your player came out 2 yrs before mine, so maybe you do benefit from an outbord Y/C adapter. I used a Kramer once and the result was very good. Better than the Extron.
I also have the Pro-version of the HM-DH4000U but I have never compared its inputs. Maybe I should....
What's your display? I don't quite understand what you promise yourself to achieve with this setup. Mind you also have to route the audio somehow.
Cheers,