As simple as it sounds. We already have an ability to zoom out with a mouse wheel. It would be nice to also zoom in like twice as more, not by default but with a mouse wheel as well. For me the maximum level zoom isn't enough cause I play with extreme render distances and want to see my base from far far away.

I would also really wish this change. I'm making a modpack where players can use an optifine-styled zoom without any requirement, and a spyglass zoom with zoom in and out feature and a much higher limit, this is really needed, thanks!

I tried to fork it and tweak by myself (sorry that I have very little coding knowledge), and it seems like ./mixin/MouseMixin.java line 38

SpyglassImprovementsClient.MULTIPLIER = Mth.clamp(SpyglassImprovementsClient.MULTIPLIER-(d* SpyglassImprovementsClient.getInstance().settings.multiplierDelta), .1f,.8f);

should be the zoom level cap, where .1f is the minimum FOV and .8f is the maximum.

but what is weird is that when it is changed to 0f,.8f (or even negative), the zoom level seems to still be capped to 10% FOV (0.1f) due to other stuff, which I have no idea of due to the lack of knowledge to coding and minecraft modding :|

By the way: mouse sensitivity is still reduced as expected, which means that even if the fov is capped at a 10% minimum, camera movement would still be disabled when it is supposed to be 0% FOV. Turn on smooth camera is an easy fix but it would be better if mouse sensitivity is also capped at a minimum value.