Received a response from Quinn @ DTS on FB23017010 regarding the com.apple.spaces plist restructure in Golden Gate. He confirmed no public Spaces API exists and suggested the plist change may be treated as a compatibility bug. He recommended filing an Enhancement Request for a proper API. Two follow-up questions for AppKit engineers: (1) Which Feedback component gets an ER for a public Spaces management API in front of the right team — AppKit, CoreOS, or Mission Control? (2) Is there any timeline visibility on the compatibility bug determination for the Monitors key removal?"
This post is from the WWDC26 AppKit Q&A.