If you look at the wedding forum, you will see so many brides that don´t want a sleeveless gown. They might not necessarily be heavy, they just are modest and want something to cover their arms.

If I could sew, I could make a fortune making modest dresses, and in fact, I might find someone who does, and become famous one of these days with this idea.

Why don´t you beat me to it, and do this for brides?
What line at David´s Bridal makes modest dresses? I saw one dress there with sleeves-one!!! Oh sure, they now add little cap sleeves on dresses-big deal!