He plays a part in the following quests:
Lenn's job used to be maintaining the fires at the light houses, as he says the Harpers occasional gave him some coin for doing that. But with the Blackdagger Bandits During The Hidden Coves, he mentions he used to have a sweetheart named Rohini. It is unknown if this person later became Rohini the Prohet, or if the same name is purely coincidental.
Currently, his health appears to give him some trouble, as he constantly complains about his "lumbago flaring up" and other inconveniences.