Topbar Tool Settings

Sorry, I just missed your last editing.

Not always. For example, to add a copy location/rotation/scale constraint, you don’t need to configure it in properties.
You just need to select target of constraint, owner of constraint and then add constraint.
Although for same kind of things, an addon is needed in 2.79 to add lattice, workflow could become similar in 2.8.
For mirror/skin/triangulate modifier, you may be fine with default settings.
And it would be relevant for quick effects that are using presets adjustable in redo panel.

You should add this suggestion to discussion on d.b.o.
it looks like they will stick to 2 columns principle (1 for labels | 1 for values).