The questions one might ask, Neil, might be separated into several categories: replacing 'required' pyrotechnics and replacing 'recommended' ones.

If you're talking about inshore issues, you might come to a different conclusion than offshore.

A parachute flair that is a real offshore flare is a LOT more visible than one a the surface. If you're offshore and you want to get attention, I don't know of a replacement for that.

Secondly, a smoke alert can be more visible (in daylight) than a little light. Also, if you're in a bobbing raft or boat, your ability to point a laser or bright light is limited compared to a flare.

Having said that, I've never (fortunately) been in a little raft with a flare to set-off and worry about burning what separates me from water WAY too deep to wade in :^))). Also, hold a flaming flare in a windy situation in a seaway in a drifting (and rotating) raft or boat is not easy on the skin, face, or eyes.

I like the idea of the flare -- I just think I'd keep my SOLAS parachute and other flares for a long time, in case I needed them.