Sap requires 2 materials that can't be teleported so I think it's fine as it is + the sap resource can at times be limited and take extra time for acquiring more when the magical energy is to a level for more extraction of said sap.

For single player I had like 3 set up on the edge of a plains, black forest and mistland that I just ran to from my base every now and then. Multiplayer would be harder to get the resource needed to sustain food / item progression for the whole party.