As the question states, is this task safe for a production environment? I find the permissions rather permissive, the cache directory is the one i find particularly suspicious. Write and execution permission on a code directory is somewhat suspicious.
Cheers
Write: quite obviously needed to be able to cache data
Execute: in case of a directory, it means listing is allowed – i.e. to see if a cached version exists or not
the project:permissions task is safe to use in prod, it is as strict as it can be while still allowing normal usage.
Also keep in mind that the contents of your cache directory cannot be accessed from the outside.