I just tried such a vulcanizing tape, though not 3M brand, with mixed results. I.e. it is easy to get a very solid grip, but in practical situations you want to have leeway in regulating the tightness of the grip. For this vulcanizing tape, you pass too abruptly from a loose grip to very tight.
Actually, that sounds ideal for the extender's mounts, (came in today, and of course the shims are hard plastic that has no grip whatsoever on the shiny bars...and of course, the old tube I had laying around the office got tossed in a cleanup a couple weeks ago.) and for other stuff that shouldn't move. (Thinking about a fork mounted stud to put a headlight lower - since I wouldn't be able to adjust it while riding, solid position holding is critical there.)