Dear Danial,
indeed the “setAdvectionDiffusionTemperatureBoundary” can not be used on curved walls.
You can try the “setBouzidiAdeDirichlet” BC which is a similar scheme to the Bouzidi scheme but for prescribing a fixed concentration on curved walls for ADE. However, this BC is not fully validated yet. The implemented scheme can be found here https://doi.org/10.1016/j.jcp.2012.11.027.