I think there is enough to get to grips with already during the PPL without doing the IMC as well. The objective of the PPL is to be able to fly an aeroplane in VMC. I think you need to be totally comfortable with the aeroplane and do many of the things without having to think about them too much before trying to understand the instruments.
I have over 100 hours now and am part way through the IMC but there's no way I would have wanted to do it any sooner. I just wouldn't have had the spare brain capacity but maybe that's just me.