Very grateful for the coaching on filters earlier from corkr03. That got my static, simple property/value pair checks working beautifully!
Now I need to apply a little heuristic with a function filter to calculate inclusion. I'm trying to follow the examples for function filters, but for some reason, the "allowFunctions" flag keeps getting set to false.
The full Apps.js is attached, but here are some snippets.
Here is where I'm trying to turn allowFunctions on:

After the page renders, I print out the store config's filters:

In the console, it shows that the allowFunctions flag is false, and the filterFn that I defined is not fired:

So either I am setting allowFunctions to true in the wrong place, or something built into the Rally Grid View and its store prohibits filter functions and flips the flag back to false.
OR there's a third option betraying how badly off my theory of operation is.
Oh, wise veterans, please advise.
Most gratefully, yours.