Doesn't work, unfortunately. I have same com.apple.Boot.plist in disk0s2/Extra and disk0s3/Extra,
with same (none) effect ...
Only typing in boot loader works for now...
At the moment your partition specific boot.plist will be loaded from /Library/Preferences/SystemConfiguration/com.apple.Boot.plist. This will be changed in next version.
Actually the Boot.plist file gets loaded in 2 different stages within the booter.
1. In an early stage when the booter starts, it loads its default values using the following path:
"/Library/Preferences/SystemConfiguration/com.apple.lre.Boot.plist"
"/Extra/com.apple.Boot.plist"
"bt(0,0)/Extra/com.apple.Boot.plist"
"/Library/Preferences/SystemConfiguration/com.apple.Boot.plist"
"/com.apple.boot.P/Library/Preferences/SystemConfiguration/com.apple.Boot.plist"
"/com.apple.boot.R/Library/Preferences/SystemConfiguration/com.apple.Boot.plist"
"/com.apple.boot.S/Library/Preferences/SystemConfiguration/com.apple.Boot.plist"
2. After you select a partition and press Enter, the booter will override the default values using another plist in this path:
"rd(0,0)/Extra/com.apple.Boot.plist"
"/Library/Preferences/SystemConfiguration/com.apple.Boot.plist"
"/com.apple.boot.P/Library/Preferences/SystemConfiguration/com.apple.Boot.plist"
"/com.apple.boot.R/Library/Preferences/SystemConfiguration/com.apple.Boot.plist"
"/com.apple.boot.S/Library/Preferences/SystemConfiguration/com.apple.Boot.plist"
The "fix" would be easy by adding a new entry after the rd(0,0) one:
"/Extra/com.apple.Boot.plist"
Until the next release, use the ancient old de-facto standard "/Library/Preferences/SystemConfiguration/com.apple.Boot.plist" to specify your partiton specific plist values.
Bye,
zef