I made 260-310rwkws out of an RB20 for over a decade. 70,000kms street driving and probably 60 or so track days, motorkhanas, Dutton Rallys etc.
The engine only died because I was sitting in traffic and a coolant hose under the inlet manifold had a leak and it lost its coolant during a city drive in peak hour. By the time I saw the skyrocketing temp and steam I had to keep driving another 2 mins to not cause traffic chaos in Swan St bridge in Melb. So fixed hose , crossed fingers but the head gasket had a minor leak and after 12 months with a slilghtly rough idle when cold etc was only a matter of time until I was going to havea more severe failure of the head gasket so retired the engine.
It was perfectly reliable at 306rwkws on E85 and 8,500rpm with 21psi in its guts.
The TD06 wasnt the worlds most responsive turbo but its a 2L 6 cylinder that has no problem with rpm so I call BS to the only 2,000rpm of powerband. I think the std internals are strong enough to handle the power you are after, expecially with E85 as the std rods are strong, ditto crank and pistons. If you are going to rev it as hard as I did there is no doubt some rod bolts are sensible if you are going to blueprint the motor and give it a general health check and blue-print. I dont think they really need rods and pistons etc unless you have a turbo and a fuel that will take upwards and over 25psi
On 98 i tracked it with 255rwkws. On 100RON I tracked it with a few points more ignition and boost as it wasnt so ignition sensitive so was around 275rwkws and on E85 it was golden and made 306rwkws and thats the boost I ran it
On PULP (with Plazmaman and std)