I can understand a desire to be able to put lights or other markers on the ground to mark out an srv 'track'... and flares would be good at this.
But to fire into the air to light things up? NOT very effective on higher G planets. I'm not sure how much of the surface you expect them to light up? Flares are mostly commonly used to mark a location not as a sun substitute...
How about MUCH MUch brghter ship lights and the mechanic to park your ship on autopilot just a kilometre up?