Tried as many as 20 or so conversions. The larger ones kept crashing sooner or later and it took a lot of effort to create one working scenery package. Tried level -1 to 3 in fset combined with different levels in geoconvert 9-14. I have 32 Gb installed so memory should not be an issue. Then I created a 32 GB pagefile on one of my ssd drives ( advanced system settings...performance. And there you should find the settings. I rebooted and did 5 succesfull conversions since. I even started aeroflyfs2 and flew during one conversion and it just did not crash!!!
Hope this helps some of you.