I don't think moving the subframe spacers to the bottom of the subframe would work if you have those aftermarket sway bar braces installed.
For what it's worth, looks like subaru removed that spare tire brace for MY07+
MY05-06: https://parts.subaru.com/a/Subaru_2005_Outback-25L-TURBO-5MT-XT/_54106_6029075/REAR-SUSPENSION-FRAME--STABILIZER-05MY-05MY/B13-201-01.html
MY07+: https://parts.subaru.com/a/Subaru_2008_Outback-25L-TURBO-5MT-XT-Limited/_54106_6029077/REAR-SUSPENSION-FRAME--STABILIZER-07MY-/B13-201-06.html
