sorry for the silence last weeks.
My IREX devel environment broke complete some weeks ago and I've been working hard away from my home so no time to do anything.
I also think the cause of the battery drain is due to the clock.
It didn't drain so much in my first tests, but if I remember correctly we introduced a supposedly minor change after (in the idle.sh file). I think the problem comes from it.
Now I'm doing some new tests and I expect to release some fix in a few days.