I have a mortgage on my home and choose not to pay it off early because my money is working harder in other places and for the tax deduction.
It is on my radar because it touts to help pay off your mortgage earlier WITHOUT YOU SPENDING EXTRA MONEY (i.e. no pre-payment out of your excess).
Call BS again!! You pay down the mortgage early, you loose the tax deduction on the interest. You have to use money to pay it down early. No magic is going to change that. Also important thing to note about HELOCs. Most charge interest on the peak balance during that period, not the average. If you were in the situation you could do a cash purchase, you would be more concerned with making the most return on income and you would know that you don’t pay down principle without spending the extra money to do it.
Have you produced the data yet? It would be easy to fact check the data. I presume you have a copy of the program, so it should be easy to pull the numbers out… one row per time period.