Use cases here
https://docs.google.com/document/d/1NYVGXbpZekKZcF3er4dr03P-wC2cXMohpnlvuXQq1Ok/edit#

Currently two approaches have been discussed, which have UX implications, see notes:
1) new routing policy, starting with headers based routing, and eventually to evolve into a more complete routing policy --> more intuitive for the customer
2) enhancement of current 'headers' policy --> we (product) think this option is less intuitive because it requires customers to learn in depth how APIcast policy chains work to configure the policies