I’m trying to be careful with front buttons.
The left side is already crowded, the right side is taken.
I can add stuffs at the bottom but a slider would be too much.
Also the bottom bar is currently the only UI elements that is not responsive on small screen (to my knowledge), I will need to somewhat handle this issue first (either scrollable bottom bar or force-removing some shortcuts that are not unique).
Unless you changed the settings, it’s already the case.
All the unselected objects are darkened.
If you prefer you can also display the outline of the current selection.