No direct experience with a 5 speed with drum brake, but I've been riding an XRF5 for going on 5 years with no issues. Started off with the twist shifter that came with the hub. It worked fine, but when one of my grandsons knocked the bike over and broke the housing where the cable exits the shifter, I took it as an excuse to try the trigger shifter, the DLS 50.
(DLS52 for wide range)
The shifting is flawless, right down to zero degrees f. No issues whatsoever.
I used to sell bikes with 8 speed SA hubs with drum brakes, and they worked very well when set up properly. It's the same brake as the 5 speed.