This is cool and all for certain playstyles (not long where you scavenge towns of time etc), but I wanted to make a suggestion for an alternative.

Perhaps make both vanilla maps and the disposable ones available? And then use a say 10:1 ratio for disposable and vanilla maps? Just for the sake of usability. As well as adding a new level of 'luck-based rewards' to the loot tables. (Not really immersive or logical for maps to be one-time use only, other than for new players on short burst playthroughs)

What would be a better and more immersive way to go about it (in my opinion) would be to have maps in your main inventory turn into 'drenched maps' during rainfall. Not in your backpack, just in main inventory. That would be really cool and could hurt you mid-scavenging when you forget to put your map away in your inventory.

Also, when crying baby mod? I want to carry around baby and attract zombies while I have to feed him. Just a general mod suggestion. Maybe someone has more dollins than me to commission it? I want babymomma immersion, which would be annoying and immersive as all hell :)

As said in comments.

a mod to automatically annotate the notes from those maps when you read them would be awesome, or being this a feature in this one.