Company Device Management on Separate User?
Unfortunately you can't because it would be a massive security hole.

It's called mobile device management, not mobile user management and this is for a reason - how secure would it be if all the user had to do to bypass corporate security policies was create a new user?

If you want to keep your personal data on your personal Mac secure from corporate entities and their MDM software, use a different Mac.  It's probably very feasible that the company can provide you a loaner Mac for this event.