Details in the comments but copied here for convience.
I am using RSO 2.27 and Factorio 14.20.
I have also changed a couple of the RSO settings to:
global_richness_mult = 100 -- multiply richness for all resources except starting area
global_size_mult = 8 -- multiply size for all ores, doesn't affect starting area
Map string >>>AAAOABQAAQAFBQYAAAAEAAAAY29hbAMDAwoAAABjb3BwZXItb3Jl
AwMDCQAAAGNydWRlLW9pbAMDAwoAAABlbmVteS1iYXNlAwMDCAAAAGl
yb24tb3JlAwMDBQAAAHN0b25lAwMD4yPnL4CEHgCAhB4AAwEg2hDE<<
<
This eastern side of this patch is visible on the far west of the visible starting area.
It turns out that you can land fill in the area and the mine to the stone
