Wordpress by default allows [contributor user] to post a new post but prevents [contributor user] to edit or delete his post it is okay with me but...

My idea is to achieve this while making sure that the post he does the second time is not a new post altogether as it happens by default, but just an update that appends itself to the original post with an hr tag with title as “update” and consequently thereon for any new posts by same user.

To be specific I need a plugin that performs the action after it checks the user role and not for all users.
Like if
the action must be performed only after the plugin checks the user.
For instance, I am using WP Hide Dashboard plugin to hide Dashboard from [contributor users] it checks the user and performs the action and it works well for me. I think perhaps a modification to this plugin would work or may be a separate plugin that checks the user and performs action.
Is this too much to ask for here ANY ADVICE I WOULD GREATLY APPRECIATE