The boost level will be what's at the manifold. 20psi from a single or a twin will never be the same really even on the same engine, they're different turbos so different characteristics/power bands/figures etc.
Regards twin turbos, it depends if they're sequential or non sequential. The triangle engine is sequential, so full boost from very low down, horrendous switchover flat spot, full boost to redline pretty much.
By triangle, do you mean the w**kel?
Full boost to redline is for winners. Shuts up the queers who keep banging on about high revving redlining NAs. Yeah I'll take your redline, and mine, plus boost. $2.99 Faggots!