The SAE rear indicators are red-only and either all on or all off.
The ECE rear indicators have a separate set of amber and red lights.
I've been told, unhelpfully, that "it requires coding" to switch from the SAE to the ECE indicators. I was able to dig up someone struggling with this swap, they were having both amber and red illuminate as one unit without any coding work done.
Does the GS911 support changing from SAE to ECE? I'd assume it's on the body control module somewhere?