When I upgraded from version 10 to version 11.0, and today when I upgraded to version 11.1, while some of my preferences were transferred, one set was not.

In Options | Preferences | Editor |Format | XML, in the "preserve space elements" dropdown, the four elements I had added were not carried forward. As was said above, they have failed to carry forward for each of my several past upgrades (9.x to 11.1).