Hi Kato,
I run the exact same Duralite Plus battery and reg that you are using. I'm am running on a DA IGN and it has caused no issues. I have not seen nor heard of any issues using this setup with IGN's. The 3w IGN's have had many problems over the years. They have had cap failures because of bad design, coils that would give up or become weak causing erratic running, misfiring, or dead cylinders, and the latest problem is with the units overheating. The overheating is not due to the battery or the regulator. It is another design problem. This is a known issue. They *should* cover the IGN and resolve this by fixing the underlying cause. Blaming the user and the battery system he is using is not gonna fix them.