The only command that decreases a refine level is Downrefitem. If you search in the script (CTRL+F), you'll find that it only occurs once:
set .@Drf, getequiprefinerycnt(.@part) - .@safe[.@wp];
for( .@i = 1; .@i <= .@Drf; .@i++ )
downrefitem .@part;The first line calculates the number of refines from the "safe" level, and the second line loops the 'downrefitem' command that number of times. So, if you delete those two lines, you'll have what you want.