The ObjectScale node does not output the correct values in the material editor.
This method works to tile images with a Surface Material Domain on a basic plane, but does not work when using it with the Deferred Decal Material Domain, and the decal stretches instead.
Reported in version 4.25.3 (CL-13942748); tested in version 4.25.3 and version 4.24.3 (CL-11590370)
Result: The texture does not stay the same size as you scale the decal object.
Expected: The texture should stay the same size as you scale the decal object because the texture scale is inversely proportional to the object scale.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-97213 in the post.