Video Tutorial Link

Installation

Simply drag and drop Addon .zip file into Blender, or install it through preferences

After that in Addon setting click the Add Assets Path to add Bevel Mixer tools in Asset Library
You can also move Addon Panel in any custom Panel

Addon Panel

Set Bevel

Add Bevel (Edit Mode) - creates 4 custom Bevel_Mixer attributes on selected edges, assigns a Bevel Mixer modifier with those attributes selected in properties

Offset - starting offset value for created modifier
Segments - starting segments value for created modifier
Shape - starting profile value for created modifier

Bevel Attribute - Starting Value for created attributes

Attributes

In this section you can pick Bevel Mixer modifier on the object to sync corresponding Bevel Attributes to adjust

Also Select button selects all edges with the attribute

Adjust Bevel

Interactively change the attributes value in the Edit mode

Single Mode - Change all 4 attributes together
Left/Right - Change Left and Right side Bevel separately
Start/End - Change starting and ending bevel separately (Primarily for use on single edges)
4 corners - adjust each attribute separately (Primarily for use on single edges)

Affector

Add Affector - creates mesh cube with defined size and sets it as an Affector in corresponding Bevel Mixer Modifier. Created affector turned off for rendering and set to Wire viewport mode. Also set as child to Beveled Object and put in separate Affector Collection

Bevel Mixer Modifier

Mode - set which Edges to Bevel
Attribute - use Bevel Mixer attributes to set the bevel weights
Angle - Simple Bevel based on Edge angle

Offset, Segments, Shape - Set Bevel Offset, segments and Profile shape

Miter - allow mitter

Profile Curve/Mesh - Use separate Object as a geometry for Bevel Profile. For proper results better to use mesh object edge curve in X/Y coordinates with 1m size

Remove Sharp - Remove Sharp attribute from Bevel outer edges if exist
Harden Normals - Align Bevel Outer edges normals to original object surface
Supporting Loop - Add extra edge loop outside of Bevel

Secondary Bevel

Creates bevel on outer outer edges of Main Bevel

Affector 

Pick Geometry to affect the amount of Bevel through Geometry Proximity distance

Amount - Value to add/subtract to the original bevel
Distance Max - Distance where edges will be affected
Falloff Outer/Inner - values to adjust falloff curve

Limit Group - turn on to limit the effect with vertex group or other attribute

Attributes

Edge attributes used for Bevel Weights

Propagate Attribute - propagate edge attributes from perpendicular to bevel edges onto bevel geometry (Sharp, Seam, Crease, Bevel weight etc.)

Bevel Mixer Tools

Flip Left Right 

Swap Left and Right Bevel Values

Bevel Number - number of Bevel Modifier/Attributes set to apply to

Flip Start End 

Swap Left and Right Bevel Values

Bevel Number - number of Bevel Modifier/Attributes set to apply to

Proportional Bevel Editing

Bevel Number - number of Bevel Modifier/Attributes set to apply to

Edit Bevel - Edit all bevel attributes at once or pick Start/End or Left/Right workflow

Distance - Distance where edges will be affected
Falloff Outer/Inner - values to adjust falloff curve
Limit Group - turn on to limit the effect with vertex group or other attribute

Workflow
Average - Mix Existing and new value according to falloff curve
Additive - adds new value to existing value according to falloff curve

Edit from Vertex

Adjust start/end bevel attributes of neighbour edges at selected vertex

Relax Bevel

Smoothing Bevel attributes among selected edges with attribute bigger than zero