RF signal will “bend” around the corners of your copper tape. There are some solution which can give you high precision positioning for sports, i.e. Quuppa.
Do I get it right that the signal strength is absolutely uniform across all directions? Some of my tags are working at their limit now through ice and snow, and if a certain tag orientation would produce even marginally stronger transmission towards the receiver, I could certainly use that knowledge.
It’s supposed to be uniform, there are no ‘professional measurements’ though as far as I know, but based on my observations the best signal comes directly ‘upwards’ (ie. when the tag is upright on the table with the breathing hole on top)