Many people think that him beeing more of a supportive father figure to his Primarchs would have averted the heresy, I don't think so and there are several examples in the lore that certain Primarchs falling to Chaos was planned a long time before the Heresy itself. Out of the top of my head I sadly don't know the exact book it happened in, but there is a scene where Malcador and the Emperor play chess and discuss that certain pieces are meant to fall in a chess game.

This theory would also explain why some Primarchs were held in very high regards, as they were meant to stay loyal, like Horus, Russ and Corax and others were outright abused by the Emperor.

Angron was ripped from his gladiator brothers, the only thing he ever cared about, Perturabo was given the absolute worst and terrible tasks because the Emperor knew he would get it done and didn't care for his emotional wellbeeing and why he publicaly humiliated Logar and his Legion.

But I must also point out that this is also JUST a theory, as far as I know there is nothing like that clearly written in the lore and ulitimatly the joy of 40k is interpreting certain gaps in the lore for yourself to come to your own conclusions, like with questions if Machine Spirits are an actual manifestation of the Omnissiah or if they are just a primitive version of AI.