Processing Constraint - Constrained Operation of Create or Validate

Summary:

Need to restrict certain roles to create a sales order of specific sales order type

Content (required):

Hello

We have Equipment Order type among others. Based on a business practice/policy, a specific group of users is allowed to create a sales order for Equipment - others cannot. So we created a copy of Order Entry Specialist role.

1. I believe the LOV for order type itself cannot be controlled by the user role; accessing the create sales order screen - please confirm if this is true/else provide a way to control LOV (we don't want to do Page Composer)