No mention is made of the practice green. This is part of the discussion of Handwritten Notes:
“Handwritten notes may contain information gained only through personal experiences of the player or the player’s caddie from the course or by watching a televised broadcast, but are limited to information gained:
While observing a ball that was rolled or played (whether by the player, caddie or someone else) or
Through the player’s or caddie’s feel or general observations of the putting green.”
Just as the players can use Trackman and alignment rods on the practice tee, I’m sure they can use anything they want on the practice green.