Customizable zoom levels for mouse wheel zoom
The current mouse wheel zoom (ALT + wheel) only navigates between zoom presets, making it incredibly difficult to use since the scale factor only doubles/halves most of the time. This is especially true when using touch mouse wheels (e.g., Microsoft surface mouse).
A setting that switches between this mode and a finer grain zoom (e.g., +/- 10% of current, possibly user-preference defined) would make this much more useful.

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Maura Dean commented
We used to be able to also customize the ZOOM percentage at the bottom of the screen. Why did this function change? I agree with the original poster. Please update this function to include customized zoom levels!
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Oz commented
Customizable zoom levels would be very helpful. For our work, there are large gaps between useful zoom levels and half of the available zoom levels are useless to us. They're either zoomed way too far out to get anything done, or zoomed too close for our needs.
The ability for the user to add additional zoom levels at key points like 85% (about half-way between the existing 66.7% and 100% zoom levels) and 125% (half-way between 100% and 150%) would be a thousand times more useful than being able to zoom out to 3%. Is a 3% zoom level useful for anybody's workload? That turns the entire enormous work area into about 1/8th of my 1080P display.
Wouldn't the area marked in the attached screenshot be the sweet spot for many/most workloads, with the rest being used only occasionally? I'd love to be able to trade the ones I never touch for zoom levels I would use every day.