Thank you for such a thorough book...
This book does discuss autossh [1] which I came to know about recently while setting up my dynamic home ip (w/ CG-NAT) as the exit node in a wireguard network to overcome geo-restrictions on streaming services when traveling... :p
autossh [1] is such a simple and useful utility, wish I had known about it earlier when any connection changes in VPN/WiFi used to break my ssh tunnels to the corporate network during development...
If you're a frequent user of ssh tunnels, do check out autossh... ;)