Users are no longer able to copy paste user items from a 'Multi User Picker' Custom fields (Related to JRASERVER-32092)

Issue Summary

Since Jira v8.21.x, changes introduced by JRASERVER-32092, there's a change in the way the user items are displayed in the UI. Previously (before 8.21.x) clicking on the edit button on a 'multi user picker' CF would show the user items as texts with user avatar and now (post 8.21.x) the users show up as lozenges/labels.
Due to this, users can no longer copy multiple users from one custom field to paste them We can no longer copy those user item lozenges and hence can't paste them into a different field.
This is a loss of functionality introduced by the feature implementation and hence reporting it as a bug.

This is reproducible on Data Center: yes

Steps to Reproduce

1. Add a couple of users in a Multi-user picker CF and try to copy the users

Expected Results

User is able to copy the user items from one CF to another

Actual Results

User can no longer copy the user item(s) in the UI.

Workaround

There's a workaround, although with a twist.

We can disable the new behavior of muti-user picker fields with this Dark Feature:

jira.no.frother.multiuserpicker.field

Adding this dark feature will revert the way user items are shown in the CF and go back to texts in edit mode and you should be able to copy and paste the usernames from one CF to another.
This, however, causes the autocomplete dropdown to be unavailable, so you have to use picker in a pop up.