Unity package was submitted with Unity 2019.3

-Universal Render Pipeline (URP) package
-High Definition Render Pipeline (HDRP) package

On both Render Pipelines there the custom shader with channel packed materials under the name ''RavenWing shader'' works with URP and HDRP using the same texture/material/shader.
The custom textures are like this: using 2 textures (channel packed)

- AlbedoGloss
  (RGB+A) RGB= Albedo A=Gloss

- AmbientOccNormalMetalNormal
  (RGB+A) R=AO, G=Normal (Y), B=Metal, A=Normal (X)

Using 2 textures instead of 3.

But there is also standard HDRP material (Basecolor,Maskmap, Normal) and standard URP material (Albedo, MetallicSmoothness, Normal).

Unreal Engine project files was submitted UE4 4.24

There is also a custom shader material using 2 textures (channel packed)

- AlbedoRoughness
  (RGB+A) RGB= Albedo A=Roughness

- AmbientOccNormalMetalNormal
  (RGB+A) R=AO, G=Normal (Y), B=Metal, A=Normal (X)

And there is the standard UE4 channel packed material using 3 textures.

-BaseColor
-OcclusionRoughnessMetallic
-Normal

You can use any setup you want. It's already done in each project Unity URP, HDRP and UE4.