6x45 with the 87 gr vmax at ar length

I've not used them on warm targets but shot them for decades in matches with great success. No reason they wouldn't work well on predators.

Nothing wrong with the 87's but considering in an AR you're pretty limited on OAL if you can get your hands on some 75gr Vmax I don't think you'd be disappointed and even with Benchmark, which is maybe a little on the fast side for optimum velocity, depending on barrel length you could probably get the 75's launching at around 2900 vs the 87's at 2700.

My "go to" coyote bullet in my 12tw 6-284 is 75gr Vmax w/H4350 and they flat hammer coyotes and are pretty destructive, which I'm completely fine with. At 6x45 speeds I'd imagine they wouldn't be nearly as explosive on hides.
I would go with the 75 gr V-MAX!

When I could shoot lead bullets at coyotes the 75 gr V-MAX was my favorite coyote bullet out of my 243 Win.