I'm a righty, so all 4 of my rifles lights are at the same 10:30 position. They are all mounted via Arisaka mounts. 2 of them are Surefire Scouts with tape switches, which work well with inline mounts. The 3rd is a Cloud Defensive Rein 3.0 and the 4th is a Cloud 3.0 head and legacy body with a Surefire tail cap and Unity Hotbutton. Their wires are directed towards the rail, so they work better with offset mounts.
All 4 rifles have red dots that have been proven in situations that are far beyond what they'll ever see in my ownership, so I've never bothered with buis. I'm of the same mentality, that if any of them fail, I'll have way more concerns than not having buis to flip up.