MacOS – ny way to set a MacBook Pro to not sleep when you close the lid

Considering that PMStats reports a hibernation write time of over eight seconds, this leads me into thinking it is the RAM content.

Exactly. Your RAM contents are written to the disk, in the default sleep mode, called "Safe sleep", which takes longer the more RAM you have. You can modify this with the PMSet command in terminal.

sudo pmset -a hibernatemode 0

and then reboot.

If you disable this option, you can also remove the sleepimage file from /var/vm, and reclaim 8GB of hard disk space. Do note that you will lose data then if you sleep for too long and the battery dies.

There is probably not going to be an offical way to do this but, what you want to do is disable the laptop from sleeping when the lid is closed. And adujust the energy saver settings in System Preferences to never let the Computer Sleep. Then use your existing VPN tunnel as expected.

See Is there any way to set a MacBook Pro to not sleep when you close the lid? for suggestions on ways to stop your Mac Book Pro from sleeping when the lid is closed.

The top rated suggestion was downloading InsomniaX to disable sleep mode.