Simple suggestion for developers

I greatly appreciate that the game remembers my choice of plants from one play of arena and/or penny to the next as well as the reload feature.  I do find it annoying that they don't persist if one does a plant selection in some other section such as plant of the week.  Why not have each area have it's own memory...surely that would be easy to implement and consume negligible resources.  E.g. I select my plants for the arena and select different plants for penny pursuit and when I return to arena, it's set of plants is remembered.  Currently, the choices interefere with each other.