Isn't vacuum used & switched by diverter valve to permit secondary safety boost pulses & not the WG control?

Vacuum is not used to control the WG in a 1.8T, isn't it boost always diverted to WG spring motor and blocked by N75 to permit WG closed by spring tension and boost increased by this method of N75 recirculating boost to turbo at T connection?

Isn't the spring strength of WG air motor also equally Important to hold exhaust to turbine up be spun and permit boost build up?

Don't you think you should read SSP & RTFB for explained operations of design & function?