Hi,
There‘s no need to „add - map“ these assets within the Forest Pack plug-in on render nodes from the UI. Just please configure on all render nodes corresponding paths to these assets stored in the 3dsmax.ini. The ini file is located by default here:
C:\Users\<yourUsername>\AppData\Local\Autodesk\3dsMax\<your3dsmaxVersion>\ENU\3dsmax.ini
Also, generally, we recommend resolving all references used by Forest to absolute UNC paths. It's not necessary, but usually, this way you avoid any texture path issues while using distributed rendering.
I hope that helps.
Best regards,