Does Stripe Express support adding multiple users under the same account?

Yes. You can add additional team members from the Profile tab.

Under Team members in the Profile tab, you can invite team members and remove team members. Note that your account can have different team members for each platform it is associated with (i.e. if you invite a user to share your Kavholm account and also have a Deliverly account, the user will only be able to see Kavholm activity until you also invite them to the Deliverly account)