I really don't see a point in that, honestly. If someone has flames opted out, they have them opted out because
a.) their computers can't handle the particles,
b.) they're tired of looking at gigantic globe/rain/obtrusive flames, or
c.) they really just don't like looking at flames.
Adding a smart feature of sorts could be useful I suppose, but if someone really wanted to look at flames they'd opt in until they needed to opt out.
Flame Specific Rules
A) Do not create, request, buy, sell or wear flames that cause serious lag in-game or obstruct being able to play the game.