▪Animator interactivity:  

MG-Picker provides powerful and very rich ways for animators to interact with pickers.

Make sure you are in animator interactive mode, which means this button is being selected:

Selecting: The same selecting rule as Maya.

LMB click on select-button / Frame selecting: Replace selection.

CTRL + LMB click on select-button / Frame selecting: Deselect.

SHIFT + LMB click on select-button / Frame selecting: Toggle Selection

Holding ALT while you are selecting, the same select rule will be applied to the select button mirror buttons, which means hold the ALT frame select a select-button, and its mirror button's member will also be selected/deselected / toggle selection.

LMB + Double-clicking on a select-button, will select the clicked button's members, as well as all the child select-buttons' members. To utilize this feature,  the select-buttons should be linked with parent links.

CTRL / SHIFT + RMB click on select-button: will popup the button's member view to perform the more in-depth selection.  The same select rules applied to the member view.

Click the tear-off button of the member view, you just made the popup member view into a normal MG-Select Helper window.

Command Button: Just LMB click and release on a command button to execute its codes.

Pose command button：  LMB clicks on it to apply 100% of the pose, CTRL + LMB clicks on it to apply 20% for each click, SHIFT + LMB clicks on it to apply 50% for each click.

Attribute Button: LMB clicks on the value area of the attribute button, which will trigger its value change.

Starting from v2.3, the boolean and enum attribute button will not be selected when you click on it, regardless it is label area or value area.

To trigger the MMB attr-nudging tool, the only reliable way is to frame selecting these attribute buttons.

 Each time an attribute button is selected:

The current tool of Maya will automatically be switched to the attr-nudger tool that comes with MG-Picker Studio, hence you could MMB drag in the 3d viewport, and drag in the horizontal direction to nudge the attribute controlled by the attribute button(s).

Slider : Same CTRL / SHIFT / Alt / Double Clicking select rule apply to slider handles regarding the Maya nodes selection.

When moving a slider handle in picker view:

SHIFT + LMB dragging: Restrict the slider handle moving direction in horizontal/vertical. The only make sense for a 2D slider, for a 1D slider, only 1 direction is available.

Alt + LMB dragging: Moving the slider's mirror slider handle as well. This means, for instance, you could tweak the left/right mouse control in a reverse way regarding their values.

To quickly reset the attribute value of a slider:

Select all the sliders you want to reset their value, double-clicking on the background of one of the selected sliders.

Be careful, not to double-click the slider handle, which will select the clicked slider's Maya members as well as the child slider handles.

IfIf the attribute that the slider stands for doesn't exist in your scene, the slider handle won't move if you double-click its slot.

If you directly LMB double-click on an unselected slider's background, will only reset that clicked slider's attribute values.

Each time a slider handle is selected:

The current tool of Maya will automatically be switched to the attr-nudger tool that comes with MG-Picker Studio, hence you could MMB drag in the 3d viewport, drag in the horizontal direction will nudge the H-attribute while drag in the vertical direction nudges the V-attribute.

The attr-nudger tool doesn't support ALT to nudge the mirrored slider attribute, since the alt key in Maya is for viewport navigation, but it does support the SHIFT key while being MMB dragged, which constrains the dragging direction to horizontal/vertical, and the CTRL key to nudge the attributes in smaller steps.

Left / Right Clicking Menu of picker item:  Each picker item could be attached to a left/right clicking menu with it, even the picker panel.

This is done in the picker designer phase.

For each item that contains a right-clicking menu, there will be a small solid triangle in the shape. Just right-click on the item to pop the menu.

For each item that contains a left-clicking menu, there will be a small angle bracket sign in the shape. Just left-click on the item to pop the menu.

The menu could be a marking menu.

 You can right-click on a picker panel's content area to use its right-clicking menu, for left-clicking menu, the only choice is left-clicking the panel's title area.