The embedder ABI must support full backward and forward compatibility. The engine receives an array of FlutterEngineDisplay from the embedder - the engine must not assume it receives the latest version the FlutterEngineDisplay struct here: https://github.com/flutter/engine/blob/4c6c259bad0e2939b9a4a63bf957c3e33a0ae4e6/shell/platform/embedder/embedder.cc#L2871-L2878

Instead, it should inspect the structs it receives and access elements/members safely. For example: https://github.com/flutter/engine/blob/4c6c259bad0e2939b9a4a63bf957c3e33a0ae4e6/shell/platform/embedder/embedder.cc#L2120-L2121