For everyone coming here after "you can't do this" answer has been marked as "correct" - You can absolutely do this, very simply and easily with a customization.
Use this information from here, we will set the homepage preference per user for Next UI:
Write a script wherever you want (such as a business rule or scheduled job) that sets this preference based on your own criteria, or own groupings of users. I wrote a scheduled job that runs every hour, which sets this preference for all ITIL users to value now/sow, and all non-itil users to pa_dashboard. You could probably make something more elegant than me, but I whipped up a scheduled job in 20 mins for our usecase.
If the link above goes dead: essentially, with your script, for each user, set a 'sys_user_preference' to whatever URL you want. If you want a workspace, set the value of the preference to "now/[workspace_url]"
