I've thought a lot about a mod like this (don't even know where to begin modding, though). Was thinking it could be based on the Il-2's VAP-250 weapon (if that's feasible). Not sure if we'd need new fire objects or could use the existing ones . If you delete a fire object in FMB it disappears over the course of a few seconds. Maybe some of this is useful as a starting point.
I've done other firebomber skins (as have MaxtheHitman, DutchErik, and Ronsperk - all should be on M4T). But be careful with mine, some are obsolete and I've updated a few. I've also got a campaign on M4T called La La Land fires for the stock game - not very realistic, but it might be worth looking at. Anyway, enjoy what we have now and hopefully a modded will become interested in this (if it's doable) or I'll finally learn how to do something with the PC besides pretend I'm a capable pilot/skinner/mission builder. Enjoy