Support for AV1 switch frames

AV1 allows use of switch frames to drop to lower resolution, this could be great while the support for spatial SVC is still not there. From the AV1 spec:

Switch Frame
An inter frame that can be used as a point to switch between sequences. Switch frames overwrite all the reference frames without forcing the use of intra coding. The intention is to allow a streaming use case where videos can be encoded in small chunks (say of 1 second duration), each starting with a switch frame. If the available bandwidth drops, the server can start sending chunks from a lower bitrate encoding instead. When this happens the inter prediction uses the existing higher quality reference frames to decode the switch frame. This approach allows a bitrate switch without the cost of a full key frame.

Is there plans to add support for this in the AV1 encoder? Is it supported in the decoder?

The issue names no files, tests, or entry points. Start by locating the AV1 encoder and decoder integrations and any existing AV1 capability tests; done would require a clear support decision plus implementation and coverage for switch-frame behavior.