I see a somewhat different delemna; will your equipment perform the way you need? Are your traps sizes and modifications correct for the job? Out of the box your know that you must be able to release every fox. I suppose that means the smallest trap that will hold a fox. Then the trap needs to be able to hold coyotes and cats. Seems to me that you are looking at a tricked out 1.5. These will hold coyotes and cats but you will surely miss a bunch.
If I were headed out to trap yotes and more particularly Bobcats, I would want lures developed for those species. I suggest you put your mind at ease, sell the fox lure on line and get a bottle of coyote and bobcat lure. Yes, the Fox will take cats and yotes and the cat and yote lures will take fox but specific lures will take the target species more efficiently. This may help just a bit in reducing your non target Fox catch.
One last thing, I suggest you set all traps with about 4 lbs pan tension. You will still get a fox once in a while but for the most part they'll go on down the road. This heavy pan tension will also tend to give you very solid pad catches on your coyotes and cats.
