Termite Shield or Not
Termites are for all extensive purposes blind. They do however constantly send out scouts to look for a meal. Any old flashing, above grade, will present a detour in their route. Insects in general do not generally know how to turn fine edges. In ten years, I've only seen two examples of free air mud tubes that could possibly beat the termite shield idea.
One made loops around an old Indian motorcycle... Evil Knievel came back as a termite... you heard it here first.
I am curious if anyone else has looked into crushed granite backfill as another way to beat termites. I read an Australian paper that the proper grade, about termite size, was too heavy for them to move.