It would be nice to have explosion-damage like seperate region flag.
I won't allow players to spread fire in their regions (possible lags), but still have it more like "vanilla", which means, that they still need to be afraid of explosion from creepers/tnt.

As I saw on wiki, there is only one flag now, which is "fire" and it can toggle fire spread and explosion damage at once.

If you dont want fire spread, use that gamerule as Cloud suggested. Dont wort a new flags only for explosions.

and you dont wanne use the gamerule for the whole world right? :3

doFireTick | Whether fire should spread and naturally extinguish

Hm, maybe I will use it like this, thanks :D