[usrusr]

> The frame is the single-most valuable component on a bike.

Depends. And parts can be fenced with much less risk than entire bikes. I doubt that trackers provide any actual safety improvement, neither in the small (what will you do with the information you might get?) nor in the big (will trackers eventually reduce the number of thieves?).

What might help, I think, are serial number registries. Rohloff hub serials can be registered by owners and checked by would-be buyers, which I think does have some of the desired effect of making those bikes less attractive to thieves.