I'd like to be able to have more control over the horizontal zoom. Often I want to see all of an I2C transaction for example, but at the highest zoom I can get. Most of the time that falls between one zoom and another so I spend more time zooming in and out and scrolling than I'd like to see the information I want.
The "highest zoom" is often driven by wanting to see the decode from an analyzer while maximizing the amount of trace I can see.
This is related to "Fixed dimension output" which is a compelling reason for better zoom management (I'd forgotten about this particular need for it).