It should work. Score and snap is fine for Durock and other similar gray mesh-backed cement boards, but doesn't work that great with Hardie Backer and its clones. You'll trash your blade, but it should cut. Might be bad for the saw itself, but a few cuts shouldn't kill it.

I use an angle grinder with a diamond wheel for this kind of thing if I'm being serious about it. You can also use a jab saw, like for sheet rock, on Durock, but not Hardie Backer.