Slow Calculations on large sheetnodes

I have a sheetnode with 8 columns of lookups filled down about 500 rows.

Needless to say, the calc times for the page is pretty darn slow.

Is there a way to speed up calc by executing/calculating only the row changed (i.e get the coords of the cell changed and only calc that row)? Or perhaps there is a way to set it up such that calcs are only run manually (or on save)?

I've modified my lookups with a preceding IF (=IF(A4="","0",VLOOKUP(A4,"view_rta/all"!$A$1:$S$10000,9,FALSE))), however this has only saved me a littled bit of calc time.

I also noticed this in socialcalc-3.js, is there a way to bypass any politeness the calc routine may have?

      if (((new Date()) - starttime) >= sci.maxtimeslice) { // if taking too long, give up CPU for a while
         sci.timerobj = window.setTimeout(function() { SocialCalc.SheetCommandsTimerRoutine(sci); }, sci.timerdelay);
         return;
         }
      }