I’ve made a great many commercial drift boat/raft floats on the Yellowstone (Paradise Valley and the lower Livingston to Columbus section), Madison, and Big Hole (multiple sections from Divide to the mouth) and Jefferson (upper section) Over the last 20 years. When fishing streamers it is always a large (2-5”) unweighted streamer on a long sink tip (usually Sonar 25/30 cold) with a short (3-4’), stout tippet (OX). Long, accurate casts are possible covering a lot of water and precise targeting of bank-side undercuts and seams possible as boats tend to not necessarily follow a smooth path downstream.
The real advantage to the unweighted fly and short tippet is it is much safer and less prone to errant casts in a crowded boat. When floating with a partner I much prefer the back seat as it opens up more water on every cast.