Investors & landlords

I am sorry you have not received any kind of response, but the post is a bit abstruse in the sense that it is difficult to determine what you would need to fully answer your question. 

You can always create a test (aka dummy) return and run through the AI screens yourself after inputting figures that roughly approximate your current tax scenario. I have modified a test return and the results for the underpayment section are shown in the screenshots below.