OK. I see now how to select objects in styles by clicking on a non-visible button to the right of the style. I get that it's not really PC anymore to have a bunch of 'toggle' button icons next to a list--> too much visual noise.

As a thought experiment in GUI design, I might try and put that same icon to the LEFT of the Styles where 2 other controls (visible and color) are. That way when a 'partial' selection is made, it would show up half-filled (as it does now on the right), thus helping the user to notice it as the OTHER buttons are toggles as well. Just an idea.

The contrarian argument, especially for CAD programs, is that users sooner or later get around to noticing the 'half-selection' mode and inquire. Certainly we aren't building an ATM (where everyone needs to be successful on the first interaction with the interface), and CAD programs can certainly demand more 'learning' from users.

Overall, I'm most pleased at the progressive disclosure of your GUI. Nice job. Clearly a lot of attention has been paid.