Most times they should start and idle but run like shit, I've had one that would not run at all, if you have access to known working one then its a piece of piss to eliminate that from the equation.
and what does your 25 turbo do at 6000, is it still holding 12psi?
My SS2.5 hyflow makes positive boost @ 2.8K and 20psi @ 3.8 and keeps it to 7500rpm
Not sure what kilowatts it make as I tune it myself
all my passengers have a big grin @ 4000
so wait six months, as Hypergear is investing in a 32gtst and developing turbos for the rb20...
it might not make 20psi by 3000, but will be pretty good
you can also change the knock timing to all +5 deg and no matter what mode you are in it will be quite fcuking obvious if it is jumping to the knock tables