Constraint
For the Mapbox globe, 5 < zoom < 6 is a distinct globe-to-Mercator morph mode. A custom layer must not independently mix globe and Mercator coordinates inside this interval.
Required approach
Use a surface projected by Mapbox, such as a CanvasSource or another draped path, during the morph. Return a GPU custom layer only at zoom <= 5 or zoom >= 6.
Verification points
Every changed geographic overlay must be checked at zoom values 4.99, 5, 5.5, 6, and 6.01, including zoom while the camera is moving.
The overlay must not:
- Change its visible geographic radius.
- Detach from the ground.
- Lose accumulated history when switching renderer.