For the Properties in Blender 2.8, we moved to a more simple and structured approach for the lists of buttons and controls, which aim to be aligned around a center-line.
However, checkmark toggles currently do not follow this alignment principle:
There are many cases where it would make sense to align the checkboxes along this center line.
Take this before & after example from the Sequencer :
The 'Cache' text on the left side represents a heading, and is used as a visual anchor to guide the eye down the list.
Here are some more before/after examples:
Checkmark + value
In addition, there are many cases where we have configurations where we have a checkmark followed by a value. Currently, we tend to use sub-panels to show this nested relationship:
It works, and communicates the hierarchy, but can often be simplified like so:
Currently there's no good way to do this while ensuring proper alignment with other items. A built-in way to do the above would help in many cases where all we need is a simple checkbox+value arrangement.
Different alignments have different tradeoffs. The center-line alignment here has the advantage that it's more aligned with other properties, and is easier to scan. It also adds overall more consistency because the checkbox is then to the left of the text.
The downside is that there can be some scenarios where there is less space for the text strings, although it is mitigated by adding header text on the left side, as with the above examples.
This may prompt us to want to change the split %. Currently it's 50/50 but could become 40/60 for eg.