Hadley's Hope Gameplay

I am huge fan of "Aliens" it has been a bucket-list item of mine for an eternity
to build a piece of the hadleys hope colony.
Its a fully functional unreal tournament map that can be played 1v1.
With every project I start I try to tackle at least one new tech or optimization approach.
This time it was decal atlasing/batching.
At a previous job I had a discussion with another tech-artist if one could create an atlas
for all the games decals and gain some kind of performance benefit by doing so
and generally enabling our artists to use way more decals. Unreal's out of the box decals
have no settings for the mapping area one can however add simple offset parameters
into material functions and at least in theory as long as everything
but that offset is identical and they all inherit from the same master material the state
changes from decal to decal should be very cheap ... and it turns out it was.