didnt know the code only takes place after turn, to mabye prevent fog from becoming useless. Although i do wish this mod becomes a reality in custom games
Can take place for other events as well. But yeah, for the purpose you asked for here, there is no good way to display it to the user.
I did briefly wonder if making something like 'joint strike' would be interesting. Where you get a bonus for flanking basically. It's the only way I can think of at the moment anyway