When there's http2https redirect already for http setup, I wouldn't go nor I see a need with inserting X-Forwarded-Proto into that either through http profile or through Irule.
The intention of X-Forwarded-Proto is to let the end server know what the client machine protocol its coming in with. Its similar to the XFF - To know the original source ip.
X-Forwarded-Proto often helps to avoid continuous loops, especially when the connections are proxied & the applications resources are having absolute path, thus including the protocol causing it go on continuous loop.
You can insert X-Forwarded-Proto using the http profile insert or through Irule for the https setup.