When does the formation of the compact remnant (neutron star or black hole) occur relative to the visible explosion?

Answer

Essentially at the moment the light of the supernova peaks

The core collapse that generates the remnant is the mechanism that drives the supernova explosion itself, meaning the compact object is formed instantaneously at the start of the peak light emission.

When does the formation of the compact remnant (neutron star or black hole) occur relative to the visible explosion?
starsupernovaneutron starblack holeremnant