The invention provides a coextrusion feedblock having a flow adjuster, a viscosity compensation device, an actuator, a central extrusion conduit, and a coextrusion conduit. The invention also provides a coextrusion profiling insert assembly constructed to be mounted in a coextrusion feedblock. The insert assembly has a flow adjuster, a viscosity compensation device, and an actuator. The insert assembly when mounted in the feedblock has a coextrusion conduit extending between the flow adjuster and the viscosity compensation device. The actuator is adjustable to apply force to bend the viscosity compensation device and thereby adjust a gap height of the coextrusion conduit. Also provided is a method of operating a feedblock having a viscosity compensation device comprising a flex region, a central extrusion conduit, and a coextrusion conduit. Force is applied to bend the flex region of the viscosity compensation device and thereby adjust a gap height of the coextrusion conduit.