I'm for sure reinventing the wheel here but I've had an LLM generate an app that walks me through my existing tax routine I've been running with for years. Thus no real numbers go to any LLM I just give it my situation and it fills out the form.

The plan now is to retrieve the current year's tax forms then have an LLM compare them to stored versions from last year, and look for variances (e.g. new field, new form requirements, etc) all of which an LLM would excel at (whilst basic math it historically did not).