which... doesn't support streaming, afaik. hence the concern that that won't be a thing.

Technically the API does. We haven’t implemented it client-side, and I don’t think it’s implemented server-side on Scoot. https://github.com/googleapis/googleapis/blob/943102cfb5fa8811a15a4c21bd12421aadb423b5/google/devtools/remoteexecution/v1test/remote_execution.proto#L849-L857

...oh. interesting.