Using 'Which' to modify a whole sentence

[dawnngcm]

A grammar book stated,

'Using which to modify a whole sentence is informal and occurs most frequently in spoken English. This structure is generally not appropriate in formal writing.'

Do our teacher agree with the above?

[Raymott]

A grammar book stated,

'Using which to modify a whole sentence is informal and occurs most frequently in spoken English. This structure is generally not appropriate in formal writing.'

Do our teacher agree with the above?

I don't agree. I would not hesitate to write a sentence like that in an academic paper.

“The use of the technique which became known as the “Socratic Dialogue”was unknown in Greek philosopy until Plato, which is surprising given the verbal nature of philosophical teaching in that period.”