I would be careful in changing much with that line.
I remember changing those "ZoomLevels" for RFB (v1.5 or something like that) and finding the harbor overlays for the various ports will become off centered. The harbor will either appear on land, or too far out in the water. Best to not change much with them.
Might want to try the "SymbolZoom" parameter for what you're trying to do.