Re: Are notches on the bridge saddles necessary?
Necessary? Probably not.
Helpful? Absolutely!
For one thing, the notch acts as a guide for making sure the string is centered properly right away at installation. Yeah, the tension would bring it into place eventually, but then the string has to endure being pulled sideways (cutting motion) along the sharp edge of the saddle.
Come to think of it, the notches probably help protect the string from that same cutting motion when doing bends on the upper frets by holding it in place at that point. Plus, a little drift one way or another could potentially play hell with your intonation.
Then too, I’m no engineer. I could be completely wrong, but it makes sense to me. [emoji12]