Implementing dcc.Store on multi page app

Well, I wish I could say that I figured out how to fix the error, but I did not. Instead I rewrote my navigation code and moved it into my top level app layout (which is probably what I should have done in the first place) into a single callback, so that the values of the various radio button components have access to each other.

However this raises another question, which I ask here:

How long is too long for a callback function?:

Thanks for all the help everyone.