Just for your info: I had two oddities happen during tests lately, which may or may not be connected to your extension. Yesterday the mouse click point was shifted for both me and a player I tested spell templates with. First we thought that CTRL-clicking would not work for targeting tokens on the map anymore, but later I noticed that I have to place the mouse-pointer a good centimeter below anything I want to click, including window close buttons. Restart solved that.
Today while I was doing the screenshots above I dragged a second spell token to the map. When I released the mouse-button all of a sudden *all* tokens and pointers were shifted so far to the upper left that they landed a good way into the black part surrounding the map, viewpoint was also instantly shifted.
I will keep an eye on these.

