Disclaimer: This is meant entirely as a good faith post to help out newbies. I am in no way bashing people's builds or saying you can't do what you want to your guns. Just trying to spread a bit of good info.

As seen in the photos:

ARs tend to have the cheek rest basically in line with the top rail, and fairly close to the back of the receiver. Because of this, it can be difficult to get the correct eye relief on a scope without bringing the optic, i.e., placing it across both the receiver and handguard. The handguard can flex, which can throw off the zero. To get around this, the Cantilever mount was created. The entire point is to push the optic forward far enough to get good eye relief without bridging. And to raise it a bit since the check rest is in line with the rail.

Conversely, levers and bolt actions(and technically shotguns) have much longer stocks(length of pull) that angle down from the receiver. Because of this much larger height difference between the rail and the cheek rest, as well as being much farther back from the receiver, you generally want to move the scope back not forwards, and have it as low as possible to enable a good cheek weld and not have to hold your head up too high. Cantilevers are basically the opposite of what you want in that situation.

TL:DR Don't use a Cantilever or riser on lever actions or bolt actions. Get the lowest height scope rings you can that will still allow the scope bell to clear the barrel, and put it as far back as necessary for good eye relief.