Dual native gain is in all profiles but has different ISO point. Normal profiles are 100 and 640, HLG 400 and 2,500, Cine D2/V2 200 and 1250 and V-Log 640 and 4,000. On the S1H you can choose which circuit to use but the S1 switches automatically. If I get to the >2,000 range in V-Log I'll usually jump to 4,000.
I've shot in non-log profiles before in low-light but I've read that V-Log is best period (except on the S1 at 50/60p where it's currently only 8-bit).
I've shot with the 24-105 F4 in V-Log in not particularly bright room and been pretty happy with the performance.