As a rough reference I did the maths on my induction hob shown here, to see what sort of phase error would be required to turn its 3W standby consumption into -40W and I think it works out at about 15°, which is getting up there.
As a rough reference I did the maths on my induction hob shown here, to see what sort of phase error would be required to turn its 3W standby consumption into -40W and I think it works out at about 15°, which is getting up there.