All in One Loan a good idea?

[James Moss]

Hello all! 
The all-in-one loan, (according to my current understanding) is essentially a home equity line of credit in which your income minus life expenses minus your mortgage interest hits your mortgage debt principal immediately. It saves an incredible amount of years off your mortgage, however it is variable interest so that seems risky. One benefit is that this money that hits your mortgage lowers your principal on debt and yet you maintain its liquidity so its far more powerful that simply overpaying your mortgage as a mechanism to save interest over the long haul. I was wondering if this mechanism is good for people who make more than their mortgage and can save it...(if you don't then you don't really pay down debt faster so it's not a good idea) and want to buy BRRR properties and grow in real estate investments?