Example of how to dynamically remove the current registrations ticket capability (if set) from the current user.

example-multiple-caps.php

<?php
//* Please do NOT include the opening php tag, except of course if you're starting with a blank file
add_action(
    'AHEE__EE_Registration_Processor__trigger_registration_update_notifications',
    'my_remove_one_time_invitation_from_user',
    10,
    2
);
function my_remove_one_time_invitation_from_user(
    $registration,
    $additional_details
) {
    
    //No need to check if $registration is an instance of an EE_Registration as its done in before the action is called.
    $registrations = $registration->transaction()->registrations();
    
    foreach($registrations as $registration) {
        
        if($registration instanceof EE_Registration) {

            // Pull the registrations ticket object.
            $ticket = $registration->ticket();

            // Check we actually have an EE_Ticket object.
            if($ticket instanceof EE_Ticket) {
                // Pull the capability set on the ticket.
                $cap_required = $ticket->get_extra_meta('ee_ticket_cap_required', true); 

                // If we have a capbility that begins with 'has_unique_invitation_code' set on the ticket and the current user has that cap, remove it from the user.
                if( !empty($cap_required) 
                    && current_user_can($cap_required)
                    && strpos($cap_required, 'has_unique_invitation_code' ) !== false  
                ){
                    $user = new WP_User(get_current_user_id());
                    $user->remove_cap($cap_required);
                }
            }
        }
    }
}

example.php

<?php
//* Please do NOT include the opening php tag, except of course if you're starting with a blank file
add_action('AHEE__EE_Registration_Processor__trigger_registration_update_notifications', 'my_remove_one_time_invitation_from_user', 10, 1);
function my_remove_one_time_invitation_from_user($registration) {
    // Pull the registrations ticket object.
    $ticket = $registration->ticket();

    // Check we actually have an EE_Ticket object.
    if($ticket instanceof EE_Ticket) {
        // Pull the capability set on the ticket.
        $cap_required = $ticket->get_extra_meta('ee_ticket_cap_required', true); 

        // If we have a capbility that begins with 'has_unique_invitation_code' set on the ticket and the current user has that cap, remove it from the user.
        if( !empty($cap_required) 
            && current_user_can($cap_required)
            && strpos($cap_required, 'has_unique_invitation_code' ) !== false  
        ){
            $user = new WP_User(get_current_user_id());
            $user->remove_cap($cap_required);
        }
    }
}