I think recompiling this launcher using the latest version of the Google Flutter Desktop Embedding will solve the text scaling issue with your launcher since it is easier to use.
Or since you are busy, you can share the build steps so we can help in the building of the launcher using the latest version of FDE.
Can you update the launcher using the recent https://github.com/google/flutter-desktop-embedding/ as they have fixed the text scaling issue on linux and windows for standard non-high resolution monitors.
Here is a screenshot showing sample app using this launcher. The text is showing but scale is too small for standard monitors.
Here is a screenshot showing sample app using https://github.com/google/flutter-desktop-embedding/. They fixed the scaling issue for standard monitors.
I think recompiling this launcher using the latest version of the Google Flutter Desktop Embedding will solve the text scaling issue with your launcher since it is easier to use.
Or since you are busy, you can share the build steps so we can help in the building of the launcher using the latest version of FDE.