I have always wanted to put some type of compass on my cat as I'm sure I miss quite a lot of shifts without one. The problem is being able to read it from the wire.
The Tactics seem to have very small screens. At the last Gulfport local race there was a guy (Pete I think) on an A cat with one of those Velocitec units.
https://store.catsailor.com/pc/viewPrd.asp?idcategory=0&idproduct=27169 He had it mounted on a swivel, on a base plate, at the front and bottom of his mast. When he would tack, the swivel (with bungi cords tied to front beam I think) would rotate the unit around to the other side of the mast so he could read it on either tack, and the numbers are twice as big as the tactic's so he said he had no problem reading it from out there. It reads out speed as well.
I would love to put something like that on mine, I don't really need a coundown timer as I use my watch, and really, with under 20 seconds, I'm only looking at the rest of the fleet anyway, not my watch.
His setup might not work with the self tacking jib though, only on a Uni setup, and even then, I would worry about the spin sheet getting wrapped around it somehow, and flicking it off into the ocean. I've seen that done with the tactic's mounted on the pole. Very expensive to replace!
Another option would be to buy two units, mount one to each side of the boom...also very expensive put they probably won't get tangled and lost.