I use TPT on external drive that I plug into different PCs, and shared directory feature is actively hurting my experience, how do I disable it to make TPT portable again?
There are two ways. One way is to use the ddir parameter to set the data directory to somewhere on your external drive.
The easier way is to copy powder.pref into the same folder that has Powder.exe in it. If the preference file is next to TPT, then all settings and directories get loaded from that folder.