Let’s say I roll a 1 and use the visitor center to change it to a 6. Do I then draw a straight path or crossroads? It says in the rules ‘using the same unmodified die results from the Acquistion Phase’ so I’m guessing that there is no way for you to control what path pieces you may build? I’m assuming you can’t reroll the dice just during the path phase?
For the sake of clarity and not having to remember old die results, using a +/- number to "modify" a result would be temporary and you would forget you modified it in the next phase using the originally rolled value.
Rerolling a die doesn't modify the result, it replaces it so you would use the newly rolled value in all future phases.
So in your example you would use a 3 and a 4 in the path phase.
Sorry this is confusing. Its something were actively addressing in the new version of the game to make smoother and more streamlined.