Vector displacement maps can contain negative values (and this one does), so you also need to disable "clamp" under the texture's "colors" rollout. Also, you need to apply rotation since the by default Blender will import Zbrush obj's with a 90 degree object rotation to handle the Y-up/Z-up conversion, you want that applied to the base mesh, not the post-modifier object transform. Once you do that, the correct value reveals itself (it's 27).
vTangent = disabled (world space map, see below if you need tangent)
exr output = on
Flip and switch = 27
Mode = RGBtoXYZ
Midlevel = 0.0
Scale = 1.0
Coordinates = UV
Apply rotation after importing to bake the axis flip, but DO NOT apply scale. (if you apply scale, you must compensate with the modifier's scale setting)
Displacement map (texture panel)
Color space = non-color ("linear" or "raw" should give the same result by default, but are technically not "proper")
Clamp = disabled
If You Need Tangent Space Displacement
Blender does not support tangent-vector displacement as of the time of this post (this will hopefully change sooner rather than later). In the meantime though, there's a trick to get the same result. The multires modifier stores its data in a way that can be applied post-deformation, with a deform modifier(s) above the multires modifier. If you put your displace modifier underneath the multires modifier, subdivide to your max needed level, then apply the displace modifier, it will copy the result INTO the multires modifier! Essentially transferring your zbrush sculpt into a Blender sculpt. You will get a warning about the displace modifier not being first, ignore it. That "unexpected" result is the one we want. You can then put your deform modifiers above multires (armature, curve, whatever you need) and lower the viewport level on multires if you like. It should function exactly like you'd baked a tangent-vector displacement map.
Side note: shoutout to NudelZ on BlenderArtists who taught me basically everything in this post.