If a user has permission to publish on multiple sites, he by default publishes to all of them. If he wants to exclude some sites, he needs to go in each one and turn off the post for that site. This is ok if you have several sites, but on +100 sites it is a very time consuming task.
It occured to me that we could use one user account for publishing on one site and another for publishing on multiple sites, but again, if you don't want to publish on all 100+ sites, you still have to invest a lot of time to disable the post for unwanted sites.
I found this field type plugin, but i am not sure if it can accomplish what I want. https://github.com/eastslopestudio/craft3-sites-field
I think something like a list with checkboxes would be ideal for this (like the one in user permissions for Sites) with the current Site being automaticaly initially checked. Or a multi select field maybe.
Is something like that doable? If not with core Craft then maybe with a plugin?
Thanks in advance for any advice!