Why does it not allow you to write a temporary file in safe mode 1s?

Question

1C

Good afternoon!
There is processing, we adapt it to work in fresh, of course, you need to set "Safe Mode" = True;
and give permission.
In the process of processing, writing to temp occurs and at this moment an exception is raised "Error when calling the context method (Write): Safe mode is set. The operation is prohibited."
Although the permission is added in the DetailOnExternalProcessing() function: