Having just finished the game with Tuck I'm feeling the same as Misery on this one - the ability to see from the off exactly what recharge stations are available on the level is very useful for planning your approach to the level. So i'm not sure he needs a buff at all, however if others do...
I think any further boost to his powers on the 'dungeon map' might be overpowered... 'poison terminal' knowledge from the off might start to feel a little cheesy?!
One possibility i can think of that would fit with his 'objective knowledge' skills would be on the city map.... though again this might be overpowered... but what if he could apply his skills to locating what he considered to be the most important objectives on the city map to help against the coming robot attack...
maybe at character selection you got a drop down menu with a choice of selecting one of four possible mission types - robot command centers (-5 days), assasination, lion's den, bahmut upgrade (epic exos) - the locations of your selected 'primary objectives' would be evident on the city map from the beginning helping you to direct your progress towards them.
like i said maybe thats a little too strong but its an idea
EDIT: or maybe forget the drop-down menu and just give the city map locations of the epic exo upgrade missions? as getting to these relatively quickly would probably always be most peoples 'primary objective' ?