The STI 6-speed gearbox was the standard manual for post-FL 4Gen Liberties, but the EJ257 was a lucky inclusion for you! The GCF was either herr or arriving at the time, there were a lot of variations in the Liberties at the time - there are reports of different flywheels across the same model cars, etc.
Hey Manaz you are correct of the most part, You're Subaru kung-fu is strong

, but it does get strange with mine.
My October 2006 MY2007 Liberty GT-B was one of 40 wagons delivered to Australia along with 40 sedans. These were the very first 40 of each with the 2.5ltr EJ255.
Of each of the 40 sedans and wagons 30 were 5 speed automatics that were de-tuned from 196KW to 186KW to protect the auto. 10 Sedans and wagons were delivered as you state, with the STI 6 speed manual and the 196KW EJ255 engine. No manuals were ever delivered to Victoria only NSW and WA according to Subaru.
My wagon was one of the 10 wagons and it was one of only 4 in silver from the very first batch, it was delivered to Scuderia Veloce Motors in Rosewood Sydney where I bought it from and drove straight home to Victoria.
I scoured the earth for a manual Liberty wagon back then

it was 7 months old with 10,000km and was a leased vehicle returned, as the first owner traded up to a 2007 STI Liberty wagon that came out mid 2007 in the first STI batch, but these also had the EJ255 engine @ 205KW.
My car had the EJ257 236KW WRX STI engine and had a factory installed set of JDM developed rally sport 6 speed close ratio gears in it not just the STI 6 speed gearbox.
It also had a clutch physically the same as the WRX STI clutch, with the recessed flywheel and near flat pressure plate, but it had a 1100kgf pressure plate assembly that cannot be purchased as a part from Subaru, the replacement part is the standard 950kgf heavy duty WRX STI clutch with recessed flywheel according to Subaru.
As far as I know the other early 6 speed manuals did not have this clutch assembly but had the heavy duty flat flywheel clutch assembly, but over the years I only saw 1 other GT-B Liberty clutch and the flywheel was flat.
I'm not sure about the Liberty STI clutches I've never seen one. As you state there were several clutch and flywheel assemblies in 2007 to 2009 Liberty GT-B's and STI's.
I had the details traced back to Japan by STI Docklands Melbourne in 2009 and they advised the car was unique, as far as they could find out, no other was built this way.
I still shed a tear for this car today.
A crying shame it was written off. Were you a member of club.liberty.asn.au?
No I wasn't, I did read a bit on there, but I was way to busy back then for forums

I've slowed down a bit these last 5 or 6 years.