Systemwide default mouse focus

Hello,

I am preparing Ubuntu 20.04 for a large group of users.
The desired behavior of the interface should be "focus on hover" which can be obtained at user level via gnome tweaks.
How can I enforce "focus on hover" as a systemwide default? I would like to avoid bothering each user to change it by hand.
A pointer to documentation about changing other types of gnome default behavior would be appreciated as well.

Thank you,
Florin