The ability to choose the increments at which scrolling zooms in and out. Right now it's just set to 1, which can take a while to zoom in and then back out. If we could pick it to be like 2, 5, 10, or even more per scroll that would be nice. Maybe even two modes so you can do a fast zoom, hold modifier key for second increment.

Also the ability to flip scroll functionality for zooming. Right now scrolling up increases FOV and visa versa for scrolling down, which of course makes sense, but I'd prefer it being the other way. I see it as a visual thing, not as a numerical thing: scrolling up to get closer, scrolling down to get farther away.

I'm pretty sure I already added the Ctrl key as a modifier at some point, but it might only be in the 1.12.2 version atm. As for the other stuff, yeah I can add that at some point.

I recommend:

1. A setting that lets you set the increment.
2. You can set it to negative for a reversed scroll direction.
3. Instead of adding/subtracting the increment, multiply/divide it (in this case (2) should be the inverse instead of the negative) this way, even when zoomed in a lot, it is still possible to easily zoom in even more. This makes intuitive sense and does not cause rendering to stop when 0 FOV is reached (because 0 FOV will never be reached). A multiplier of 1.1 works quite well for me. Specifically, I changed this line to double newValue = Configs.Generic.ZOOM_FOV.getDoubleValue() * (dWheel > 0 ? 1 / 1.1 : 1.1);. This line can also be quite easily changed to match OP's initial suggestion, by changing the 1/-1 that was there originally.
4. The "scroll to adjust zoom" should be mentioned somewhere in the settings. I did not know about it until I found this issue.
5. A change in mouse sensitivity depending on the amount zoomed in and on the default sensitivity and default FOV.

I do not know a lot of Java so I am hesitant to make a pull request for this.