The panel (Palette) opens and closes with the AvcPalette command. In order to avoid pauses when selecting objects, it is recommended to close the palette when it is not needed. Data is loaded into the palette as soon as you select something in the drawing (before calling the commands). If you select many objects at once, then the A>V>C> properties palette does not work like a regular property panel. A separate tab opens for each type of object. Objects whose editing is not provided are ignored. Tabs available:

• Reference - block insertion = block reference. To edit block attributes and block parameters. As you know, a block can be inserted into a drawing many times. Each time a reference is created that describes where to show the block and how to rotate it. And each reference has its own set of mutable attributes. I preferred to place the properties of the block reference separately from the properties of the block, on different tabs.
• Solid - for all solids. Allows you to edit additional properties of the solid: Mirror, Sweep, and Texture.
• Metric - for measured solid only. There are most of all properties and you can change the materials of edges and covers. Use the SolSize command to measure solids.
• Selected Face - selected solid surface. The drop-down list of cover materials will contain only materials suitable for covering and edge bangings.
• Polyline - for polylines and legacy 2D polylines. Allows you to close the polyline, view, and change the direction of the loop around the closed polyline.
• Circle - The radius and diameter can be changed.
• Curve - for all other 2D shapes - lines, arcs, splines, ellipses.
• Leader - shows a Multy-Leader properties and Smart Leader template.
• Table - drawing table properties.
• Text - single-line test (DBText) or multi-lite text (MText) properties.
• Dimension - any type of dimensions properties.
• Attribute - for Attribute Definition in Block Editor
• Viewport - for Viewports (not for ModelDoc views)
• Other - all other visible objects in the drawing.
• Entity - a separate tab that shows the properties of all selected objects at once. For layer and color editing.
• Block - for convenient editing of the name and description of blocks, editing of constant attributes. In the standard properties panel, block properties are not available at all - only block reference properties.
• Group - properties of groups. This refers to a group of joint selection of model objects. You can give names to nameless groups.
• Material - properties of the material from which the part is made, density, price.
• Cover - properties of the coating material on the faces of parts. Paint, film, laminate, banding. 
• Layer - all layer properties, including material.
• Drawing - properties of the DWG drawing file. Standard and custom. You can add new properties to the drawing.

Tabs (buttons) for invisible objects (block, material, coating, layer, and drawing) are shown on a separate panel.

You can reduce the number of property tabs by turning off the ones you don't need in the settings.

The tab title shows the object ID or the number of selected objects.

Double-clicking on the title of a tab drops the selection of all objects, excluding the objects of this tab. This way you can select only solids or only polylines. 

Use Enter to save the changes and bring the focus to the drawing. In multi-line fields (Info, Description, Content...) use Ctrl+Enter.

Use Esc to discard changes to the current field. If you have not changed anything, then Esc will move the input focus to the drawing. Pressing Esc again will work already in the drawing field and will cause the deselection of objects.

There are three different bookmarks with solids: Solid, Metric, and Selected surface. But you will never see them at the same time. Only one of them is visible. Usually, this is the Solid tab. To see the Metrics tab, you need to measure ALL selected solids. To see the bookmark with the selected surface, you must select surfaces on ALL solids.

When the A>V>C> palette is enabled in Autodesk® AutoCAD®, the PROPERTY PREVIEW system variable (preview of properties during color/layer selection) is set to 0. This fixes an AutoCAD bug when the color/layer is reset to the original one. Without this setting, you will not be able to assign color and layer in the normal property panel.

The installer that ran when you downloaded this app/plug-in from the Autodesk App Store will start installing the app/plug-in. OR, simply double-click the downloaded installer to install the app/plugin. You may need to restart the Autodesk product to activate the app/plug-in. To uninstall this plug-in, exit the Autodesk product if you are currently running it, simply rerun the installer, and select the "Uninstall" button. OR, click Control Panel > Programs > Programs and Features (Windows 7/8.1/10/11) and uninstall as you would any other application from your system.

Properties Editor (Palette) in AutoCAD is not adapted to enter long texts. You will see only the first words and will not be able to edit multi-line text, etc. 

For the convenience of entering long names and descriptions, I made 3 separate panels (palettes) with a built-in multi-line text editor, NAME palette, TYPE palette, and INFO palette. Panels can be docked to the edges of the AutoCAD window, but I recommend using a second monitor for them. 

Info editor is different in that it is not blocked with new lines and tabs. Open and close the palettes to the appropriate commands. Palettes will show data as soon as you select something in the drawing. The changes are saved when the selection is canceled (Esc, the beginning of a new command, switching documents).