Without custom code modifications, this is really pushing what can be done with XThreads, but I suppose this
could be possible, with a bunch of caveats.
You can set the
Display Item Format to something like:
Caveats:
- get_user_by_username isn't a "safe" function, but if you have the PHP in Templates plugin, it should be allowed. Alternatively, you can whitelist it by appending it to inc/xthreads/phptpl_allowed_funcs.txt
- it can run a query for every single user specified, which can place more load on the server
In theory, you could also do something similar using the Input Formatter to validate usernames, and store them as user IDs, but you still have the above caveats.