I have once doubled the amount of CEs for Alan Bond (or Juergen Bonhagen, don't remember correctly), because he proved to me that he really needed more CEs. :-)
Unless I have seen such levels from you (or anybody else), I think the current amount of CEs "should be enough for everyone" (as somebody else would have said)... ;-)
I agree with Holger, you should definetely prove that you need all of them - which I doubt you really do...
I think 256 CEs is enough for most people...if you want to use up all the CEs because you want to make a "look! I can make a super-mega-ulrta-CE level which uses all CEs!"-level, then that level will probably not be very interesting... a chaos-level, just like Ryan's chaos level which uses all map size and tons of random placed elements.