Set a variable in the config file so that rclone reads it from an environment variable

In my PR I enable reading a pre-authenticated token to access a Swift object store.
I know that if I set env_auth=True, the variables are read from the environment.
However, if I want to do a swift->swift rclone, and I need two different tokens for the two swift installation, I cannot use env_auth=True for both, because they would both read from the same environment variable.
Is it possible to write some special keyword in the config file to tell rclone to read a specific configuration entry from a different environment variable? E.g. if the value string starts with dollar ($MY_CUSTOM_TOKEN). My latter suggestion is not ideal if the variable actually starts with a dollar, though.
I also know that I could store directly the token in the configuration file, but in our setup tokens are (very) short-lived and therefore I would need to reset it in the config file every time I re-authenticate.

I think you can now put the tokens in the config file.

You can then use the config file in environment vars trick to set env vars for each remtote. How does that sound as a work-around?

Works perfectly! Thanks a lot!

P.S.: what is the release policy for rclone? (Or more specifically, when do you think the PR will appear in a release)?

I try to make a release every 2 months. We are overdue one at the moment…