Editor.enableExportUrl - how does it works?

[Xandrr]

Hello.
How can I use this variable in src/main/webapp/js/diagramly/Editor.js to disable "Export as -> URL" feature?
/**
* Disables the export URL function.
*/
Editor.enableExportUrl = true;

a.

1. Set Editor.enableExportUrl = false; in src/main/webapp/js/diagramly/Editor.js
2. Call "npm start" (in parent drawio-desktop project)
3. There is no changes in drawio application - "Export as -> URL" feature is available.

b.

1. Set Editor.enableExportUrl = false; in src/main/webapp/js/diagramly/Editor.js
2. Call export DRAWIO_ENV=dev
3. Call "npm start" (in parent drawio-desktop project)
4. "Export as -> URL" feature is disabled in application (no menu entry).

c.

1. Set Editor.enableExportUrl = false; in src/main/webapp/js/diagramly/Editor.js
2. Call export DRAWIO_ENV=prod
3. Edit src/main/webapp/index.html - replace all checks of "if (urlParams['dev'] == '1')" to be true in any case.
4. Call "npm start" (in parent drawio-desktop project)
5. "Export as -> URL" feature is disabled in application (no menu entry).

Why does not it work in variant "a"? Is it a bug, or I don`t understand something?