I have created an extension on the SysUserManagement form by adding an additional checkbox on this page, I would like this value to be saved when the user info page is saved.

This new parameter is user specific, so I would like to associate it to a user entry. The current datasource for the form includes the UserInfo table but this does not allow for creating extensions, instead I have used the SysUserInfo table to create a new column via extension of type boolean.

And then used this as the datasource for my new custom field on my form extension.

At this point, I need to somehow hook into the write method so when a user saves the form my custom value gets written as well.
I've been looking at other examples of Chain of Command and form extensions but am unable to find an example where someone creates an extension for a form, adds a new data source to their extension, and then tries to write to it using Chain of Command.
Is this possible? Is there an easier way to do what I'm trying to accomplish?
Thanks for any help!