You love calling BS, but you calling it so quickly all the time is BS.
I call it because you are full of it, wanting to accept your numbers without proof even though the violate basic mathematical principles.

You then attempt to ingrate with us by trying to sound like you are like us.

For example, let’s say this “program” actually works for a minute (I’m not convinced either way yet).

Wrong approach. You assume it doesn’t and then you run numbers to test it. You then compare the results with methodologies other people here have mentioned are similar. You still have yet to produce sample data from said program.

It would NOT be smart to pay off the mortgage early (if you could). The best thing to do would be continue to pay the monthly payment for 10 years (1/3 of a 30 year mortgage) claiming the deduction during that time, at only 6% (give or take) and putting that lump sum money elsewhere (assuming it could beat 6%).

You just proved you don’t know the math. As you do an accelerated pay-down of the mortgage.. by any means, your tax deduction reduced because the deduction is based upon the amount of interest on remaining principle. Mortgage companies flatline the payments to make them easier (and make it last longer). If you took the approach of paying 6% interest on balance and 3% of remaining principle monthly payments would be decreasing month to month (because the principle will be decreasing). The other point, made by ‘no_such_reality’ is that these programs work by doing pre-payments, using the HELOC to cover any emergencies. If there is an HELOC drawdown, the base mortgage monthly gets covered first, HELOC excess gets covered next and any balance goes to prepay the mortgage.