Symbol for bedrock is confusing when zooming

[ivuorio]

Apparently small spots of bedrock are marked with symbols instead of areas: https://www.maanmittauslaitos.fi/sites/maanmittauslaitos.fi/files/old/maastotietokohteet.pdf
Both use the code of 34100.

The problem with the symbol is that the size(in pixels) remains the same no matter the zoom level. Also the symbols are on top of roads, paths, etc. so on higher zoom levels the maps comes quite a mess.
High zoom level looks good:

Zoomed out, the symbols cover information:

I will try to familiarise myself with the code and see if I can do something about this.