I'm fine with 99.5% of ASL rules but the one that I hate hate hate is dense jungle being inherent terrain. Completely messes up sightlines that you'd usually use, and makes the maps very geometric rather than being natural looking like you'd expect a jungle to be. I'm too afraid to house rule it because I'm sure it would mess up balance big time, and I'm sure it's meant so that regular maps can be used more frequently, but still a major pain.
If I were to change the rule to preserve some of the original design decision (and enhance realism), I would say it's an inherent LOS hindrance (+1 or +2), but a LOS obstacle wherever there is a woods depiction.