WorldGen Unhappy With Lots of Space Between Cities

Experimental Build 6323
Tiles
Windows 10-64 bit

Worldgen seems to crawl to a halt when the city spacing number is set near max. This is strange because in the tooltip, it states it gets angry when set near 0. I cannot for the life of me generate a map with 8 spacing, but I generate 0 spacing worlds like its nothing. Not sure what the cause is, but it isn’t maxing out my CPU at all. It just doesn’t generate. I’ve left it running for about an hour and a half with no results.