I like that idea but maybe have it so when you build a base too close to the front line it will automatically show up and of course all purple bases stay the same as always but it would be funny seeing two factions right next to eacb other without even realising but i think with how this game is you'll probablly know a base is there already before they place next to each other. The thing is I thought when this was coming out they would be hidden so i can put a base deep in a forrest and maybe clear some trees to make and entrance for vicks and helis

Also I might add that intel dropped by troops when dead could be used as an extra method to help find bases. Nobody really picks intel up and takes it to the command tent because the reward is so small. Maybe you could add a feature where if enough intel is collected from players that came from a certain base, that intel reveals that base