For spaces with thousands of pages, the Space Admin loads slowly. Page load performance decreases drastically in spaces with >5000 pages (in local testing, it was about a seven second load time).
The editspace.action invokes the EditSpaceEntryAction.class, which makes a getPages() call:
This is done to populate the set Home Page drop-down. The current approach does not scale well and an alternative means of populating that filed OR settings the Home Page would be ideal.