Hi --
I tried to do some analysis by looking back to olden times (QY-70) as the PSR E and PSS chorus/reverb types date back decades:
http://sandsoftwaresound.net/pss-chorus-a-dusty-look-back/
To make a long story short, here are tables of chorus and celeste parameter values:
Param# Parameter Chorus1 Chorus2 Chorus3 Chorus4
------ ------------------- ------- ------- ------- -------
1 LFO Frequency 0.25Hz 0.33Hz 0.16Hz 0.37Hz
2 LFO PM Depth 54 63 44 32
3 Feedback Level +13 +0 +0 +5
4 Delay Offset 106 30 110 104
Param# Parameter Celeste1 Celeste2 Celeste3 Celeste4
------ ------------------- -------- -------- -------- --------
1 LFO Frequency 0.50Hz 1.17Hz 0.16Hz 0.33Hz
2 LFO PM Depth 32 18 63 29
3 Feedback Level +0 +26 -20 +0
4 Delay Offset 0 2 2 0
QY-70 Chorus3 has the same MSB/LSB as PSR-E Chorus2. QY-70 Chorus 1 has the same MSB/LSB as PSR-E Chorus3. Confusing? Yes, but these are probably the PSR values or close to it. None of the QY-70 presets have the same MSB/LSB as PSR, so your guess is as good as mine.
Now, the really bad news. The PSR-E series, at best, is XGlite. XGlite implementations typically don't support the XG messages that set effect parameters. Therefore, what you hear is that you get. In other words, the effect presets are hardwired.
Hope this helps -- pj