Clip Demonstrating Behavior: https://youtu.be/LuTbgsij74M
Additionally, it appears that the texture alignment overlay is always tied to the transforms of the Blinn-Phong material.
To Reproduce:
  1. Rez two prims and place them next to each other.
  2. Place a glTF material on adjacent faces on prims.
  3. Set texture mode to Planar
  4. Ensure both texture transforms of both faces do not match.
  5. Click Align Planar Faces Checkbox