How long can British investment immigrants get permanent residency?

British investment immigrants require to invest 2 million pounds in the 3+2 model, that is, first get a three-year residence visa, and then transfer to a two-year residence visa. After the expiration of five years, they can live for half a year in five years. After passing the LIFE IN UK language test, they can transfer to the UK for permanent residence, so it will take five years at the earliest for British investment immigrants to obtain permanent residence. However, during the 3+2 residence visa period, all benefits, including children's education, are the same as those of locals.