other than needing the space when using NV or a magnifier, is there ever a reason for using a cantilever mount?
Many feel that having the optic further forward on the receiver enables them to pick up the reticle faster, reducing engagement time. I’m sure there are other reasons, but I’m still pretty new to their use.
I found that the further out away from the eye it is located, the better your field of view and lessens distraction of wanting to actual focus on the optic rather than superimposing the dot over the target with both eyes completely open.
I was only slightly faster with a cantilever mount on a timer, but I am nothing more than an average to below average shooter. 
I can see that but my experience with “scout” scopes find them lacking over the traditional location of magnified optics. is the RDS being non-magnified what makes the difference?
speaking of FOV, is there any feeling over the newer smaller optics such as the T-1 as opposed to the M2,3,4 style of RDS?
I tried my aimpoint with a 2moa dot on a cantilevered mount moving it forward and back over several days and preferred it forward
I haven’t tried my micro t1 on the AR to compare, it’s on my 44 mag pistol for hunting and it works GREAT there
Related. Since magnified optics pretty much all have some specific amount of eye relief required, they have to be set withing a certain distance to the eye. RDSs having no such restriction, your placement becomes a matter of what you find gives you your best results in regard to acquisition/engagement time, FOV, etc.
Somebody with more time on RDSs, please tell me if that passes the sniff test or not?