OS/Blender/Marmoset Toolbag:

• Windows only
• Blender 2.8x, 2.9x, 3.x
• Marmoset Toolbag 3.x, 4.x
  

Installation:

• Blender->Edt->Preferences->Add-ons->Install from file…
• Define path and select Marmoset Toolbag  executable file
• Do not forget to uncheck the relative path option when selecting the Marmoset Toolbag  executable file.

How to basic features/operators(OPS):

Rename OPS:

These operators are using naming rules as for Marmoset Toolbag's QuickLoader( toolbag-baking-tutorial )

• LowPoly/HighPoly buttons(operators) based on the active object name, like for one object and for multiple.
•  Clean suffixes - Works on selected objects and cleans only names with _low and _high

Baker OPS:

All functions here are based on the active collection at the outliner. 

Add BakerGroup button:

• Should be active object selected with _low suffix
• Automatically generates collection with two sub-collections (for high and low poly objects) inside an active collection. Like marmoset toolbag baker and baker groups

Select LowPoly/HighPoly buttons:

• Select all objects with corresponding suffixes inside an active collection

Export OPS:

• Export folder path
• Export active collection. The name for the FBX file is active collection.
• Export selected objects. The name for the FBX file is an active object.
• Run Toolbag
  

Material OPS:

• Select LowPoly object for baker and press create material after baking at the marmoset toolbag. It automatically creates new material and imports all baked textures in it. Still, work in progress.

Marmoset toolbag:

• Addon automatically creates Baker and Textures folder based on the export path and name for output textures based on the exported filename.
• For now, the user has to use QuickLoader manually because there is no API interface for it, but toolbag guys promise to make it accessible in the next version of the marmoset toolbag. So if they realize it loading process will be fully automated.