The optical properties of devices derive from the flow of energy within their structure, a flow that is governed by the interaction between geometry and material properties. Through consideration of optical bound modes in simple buried-core waveguiding structures embedded in strained multilayers, we investigate how the symmetries of the system interact through the stress-optical coupling. We do so using finite element analysis, first extracting the stress distribution in the system, and then finding the eigenmodes of the fully-vectorial anisotropic Maxwell's equations. In particular, we explore how, and to what degree, various symmetry breakings compensate for one another. We illustrate this by the distinction
between global and local metrics that delimit device operability. Modal birefringence, which arises from the difference in transport velocities associated with the fast and slow axes of the waveguide, is an example of the former, whilst the optical power density illustrates the latter. We demonstrate that these, though coupled, are independent metrics.