WSPR 500kHz (too) many frequencies to watch

I might need some other receiving techniques.
Last night  WD2XSH/6  EM31js  was received strong  by G8HUH  IO81MG
I was hopping all night 510.000 kHz   for WE2XGR/6   
 and  499.600 kHz  for WD2XSH/17  (USB dial setting)  (
+160 and 80)

But  WD2XSH/6  was on  495.983 kHz  that means I had to set my dial 1500 lower  to 494.500 kHz  to receive him
And possible  WD2XSH/17  did move here too??
I would like to receive  them all ...
Now i have WSPR set 600= 499.600    other = 510.000

To have more hopping frequencies  some not used bands like   7 or 14 MHz  could be set to other 500Khz bands..

This is my short list of  current WSPR 500kHz bands:

Dial:      502.400      used in EU  
Dial:      499.600      WD2XSH/17   i used to receive him here
Dial:      510.000      WE2XGR/6     and other WE2XGR/?
Dial:      494.500      WD2XSH/6     and  /17 new freq?
Dial:      503.630      DI2AF
and possible more "private" frequencies in use
 pity that i did not know this  the propagation on 600m was good

Received WE2GXR/6   at 08:20   very late  in broad daylight  almost half past 9 local time!
Never had a decode that late.

A pity that one of the major advantages of WSPR using one standard freq 200Hz band is lost at 500kHz.