If Pythonista is already launched, the execution of URL scheme will be fine.

If Pythonista is closed or idle for a long time, the execution of URL scheme is not consistent. Here are some result I have tried:
- The last editing script is shown and the desired script in URL scheme will run after a long delay.
- The last editing script is shown but the desired script will not run
- "No script loaded" is shown and ask for script to open. Also, the desired script will not run

In all cases, there is no problem if the URL scheme is executed again.