i think i have a couple of ideas for this feature if you're interested in listening but i'll say it either ways
First :-
Maybe you'd make the monster appear depends on the territory you're wandering at the moment. And the monster remains unknown to you until you check the notice board. You can put a monster from one of the contracts on the notice or a strong monster or pack of monsters/beasts that regularly roam this specific '' territory ''. Drowners/Foglets in the swamp, wolves in the woods near Blackbough, Noonwraith in the fields of Novigrad, Nekkers east of velen etc...
Second :-
You could add a more like gameplay feature than a UI one. And make that monster that is buffed at the moment encounter Geralt more often and randomly, but still depends on the region you're in like there can't be an Alghoul crawling at you in novigrad outskirts, it'll make no sense. I believe this how it should work from the start. A buffed monster gets a boost in courage to leave its lair and attack the roads. and villages ( maybe just the roads here
) it'll add a meaning for the feature and make it less unnoticeable.
i hope you guys consider thinking about this in your next update i'd really love to see one of those features in the game