When I go into the three-dot menu from the info menu of a chat head, I don't have the option to create a home screen shortcut. This is on my Pixel 3 running Pie. My last device was 5.0 Lollipop and it does have the option, despite having the same version of Messenger (the latest).
From this Reddit thread, it appears that the same thing happens on a Pixel XL with Oreo and the option is presumably being disabled by the Messenger app based on the OS version and/or specific device. Not much I can do about that; however, the same thread indicates that the shortcut can be restored from another device and still works, so I'm looking for a way that I can create such a shortcut myself.
Unfortunately the Pixel 3 can't be rooted yet, and I don't want to backup/restore from my old device. Is there a way I can create a chat head shortcut on the home screen for a particular contact, or copy it from my old device, without root?