That's what it was! I really, really wanted to use Dart because I love Flutter (only ever used it through FlutterFlow and was duly impressed) but I couldn't get around the binary size, mainly because I'm supporting WASM as a backend so it needs tiny binaries.
How did you handle the WASM backend? That part was extremely impressive to me. But aren't the binaries practically too large for WASM?
In any case, really love what you're doing and will be following progress. Outstanding work!