Have a different profile active depending on if your primary or secondary talent spec is active.

Some frame addons (e.g. Grid2) have positioning profiles based on which spec is currently active. Due to this it can adjust the position of your cast bar as target frame isn't a priority as a healer. I've just learned to live with having my healing cast bars in an unideal position. Adding this be huge improvement to the addon if you could manage this by adding an additional level of profiles beyond the character specific settings.