Using trim sheets and a second UV workflow to create unique details on props is something I've been meaning to tackle for a while now. Previously I've used similar methods for creating variation in trim sheets using vertex colours, but this method of using a lower resolution texture to power the transitions gives the opportunity to pack more detail and visual interest into the textures.
I used models that were originally uniquely sculpted and baked for a previous project to get an idea of what can be achieved using each workflow, as well as understanding the benefits and downfalls of both techniques.
On the material there is the Trim sheet using 2048 X 2048 textures, two detail materials, one for rust and the other for dirt that both use 512 X 512 textures. The mask map parameter that is then used to drive the transitions is also using a 512 X 512 texture per prop.
Foliage, cliffs, ground scatter and ground textures all downloaded from the Quixel Megascans library.
All images and videos rendered in Unreal Engine 4.27, then edited together using Photoshop and DaVinci Resolve.