Same issue here.
We use theSMAppService.statusForLegacyPlist(at: url) API to determine if the user enabled our helper tool in the "Allow in the Background" list.
But it always returns "SMAppService.Status.notRegistered" on macOS 14.5 Beta3 even when the helper tool was successfully connected via XPC.
PS: the helper tool is registered with the SMJobBless API, and the issue only happens on macOS 14.5 Beta3.