I installed a SharePoint 2016 Farm using minroles at a client. One of the issues that cropped up is that in the Application/Search min role, the SP Foundation Web Application is installed. This throws all the third party solution licensing out of whack as they determine you have extra web front ends.
Thanks to this article, I first removed the Web Application, did an IISReset and then changed the minrole to custom.
- Anil Ferris