I looked at the config and think it was intended that Straw Golems shouldn't decay. (Lifetime = -1)

But they still disappear after one ingame day, as far as it seems.

From my experience - they disappear when I heal them with wheat. When I stopped doing that they seem to live as intended.
But rarely they they still disappear for some reason.

This is probably bug with the mod itself, not the pack. And golems have other issues, such as not dropping items to chest that's in front of them. Or not harvesting sometimes.