Hello.
foliage.ForceLOD 0 - it set all foliage lods to 0 (High quality)
foliage.ForceLOD -1 - it set all foliage lods to Auto
foliage.ForceLOD 1 or 4 - it set all foliage lods to your number (1or4) (Bad quality)
r.ForceLOD 0 - it set all mesh lods to 0 (High quality)
r.ForceLOD -1 - it set all mesh lods to Auto
r.ForceLOD 1 or 4 - it set all mesh lods to your number (1or4) (Bad quality)