Filtering fields that are arrays of strings

[Steve]

I'm having trouble using a string filter when my field is an array of strings. It works fine if the strings are entirely numeric, but not at all when they contain non-numeric characters.

Here's my stackblitz example: Filter arrays of strings

I'm aware that my model is less than ideal, and I'd rather not refactor it if I don't have to.

Is there a way to override the process() method to handle this? Is the source for process() available?