This took quite a while to get my head around.
Finally i added LabPBR shader support via specular maps.

I used LabPBR Material Standard) as a preset for the specular maps and build on it.

Actual values used - if someone is interested - can be found here.
// Note that it highly depends on the shader and their LabPBR settings

Currently specular maps are supported for all textures with multiple variants.

Added:

• LabPBR Shader support // for all existing "multiple variants"

Fixed:

• RP won't load due to unsupported characters in filename // removed filename colors

Added:

• Excessive Building 3.3.10 Support // model from bbb compat

Updated:

• Version 1.0.5 Nemo's More Ladder Variants (MStV+) // added pale_oak

Added:

• Woodworks 4.0.1 Support // models from bbb compat

Changed:

• Up to 4 different variants for vanilla & Nemo's ladders // modded ladders will be reworked in future updates
• New folder system // now category based instead of mod based
• Every object is now their own texture // improves file size & performance / also improves particles
• New pack.png logo

Added:

• Nemo's More Ladder Variants (MStV+) 1.0.3 Support // includes Nemo's Carpentry Support
• Create 0.5.1 j Support
• Create Fabric 0.5.1 f build 1417 Support
• Create Deco 2.0.2 Support

Added:

• Building But Better 1.0.2 Support
• Quark 4.0-458 Support