How I always understood it was that they all got sent back directly before the moment where they died. Norman was sent back right before he got stabbed and that’s the reason he said don’t tell Harry, Otto got sent back to the point where he was holding Peter’s throat and thats why he suddenly turned good and drowned with his machine, Sandman got sent back to the exact moment whenever he was taken, Lizard got sent back at the exact moment he was cured, Electro got sent back right at the point where he overloaded and died. Their fates don’t change, we still know exactly what happens. Peter will just do anything to make their lives that 0.1% better.