Zoom / Magnification ratio needs improvements

If After Effects adopts smooth zoom it can also keep pixel Preview as in Illustrator as an option. It is also possible to zoom to any level when Preview in Illustrator is enabled.

If you turn on Pixel Preview in Illustrator, you get the same snapping because you are trying to look at the pixels. 

If After Effects adopts smooth zooms, it will be extremely difficult to fine-tune position and really know what the render will look like unless there is some kind of override. 

@Rick Gerard I know the fixed values are useful as you described but sometimes I just want to have full control overs magnification level and I want to adjust it to my liking. Since those non fixed levels are possible I ask Adobe again. Please make it fully customisable and smooth as it is in Photoshop or Illustrator.

The magnifier and the mouse wheel (I use a mouse pad) or a two-finger drag snaps to the even multiples of zoom so you can precisely examine the edges of the pixels on the pixel grid. This is the only way to accurately position thin lines or edges in the comp for maximum quality. 

Fit gives you random values but is useless for examining things at the pixel level, so dragging or scrolling to the next zoom level is useful for lining things up.

I've seen hundreds of posts wondering why thin lines look bad, or their scrolling or rolling text looks uneven. The answer is that the pixel grid must be respected and understood. The credit roll or scroll problem is called judder and is solved by moving the layer an even number of pixels per frame.

I did misspeak when I said zoom smoothly. I should have said to zoom smoothly in or out of a comp with the mouse. I do not select fit when I'm working on a comp, no matter what size the comp panel is, because, as a designer, composite, and animator, I want to know precisely where my elements are on the pixel grid so I get maximum quality. If I need to add lens blur to a composited element to match the footage or motion blur to make the shot work better, I can see exactly what I'm doing if I can see the actual pixels. Looking at a comp at 43.8% won't tell me anything about the actual quality.

When working in Illustrator, creating graphics for video, I always turn on Pixel Preview and Snap to Pixel in the View menu to ensure that the graphics I make are properly lined up with the pixel grid, which is essential when designing graphics for video. 

I cannot think of any situation where a magnified preview of 1.5 or 2.66 pixels would give me an advantage in designing my shot.

@Rick Gerard, you can have any zoom when "Fit" is selected by scaling the Comp window. This is not a proper solution as I don't want to scale the window to have a certain zoom level. That's why I dont understand why the zoom is still limited to fixed numbers as it can work with any number. 

How can I smoothly zoom to any number using mouse?

The zoom presets make sense to me because you can't view 1.5 pixels. They have to be interpreted. If you have comp resolution set to Auto, then RAM previews at 50% will run twice as long as a RAM preview at 100%, and the render time per frame is also cut in half. The math just doesn't work if the resolution is set to 75% because you can't calculate 1.5-pixel data as quickly or as efficiently as just looking at every other pixel.

You can still smoothly zoom into the comp panel at any magnification with a pinch or appropriate mouse move if you need to get in there and look at something specific, but you need even multiples of the pixel grid to make sure that horizontal and vertical rows of pixels line up with the pixel grid.