This is really just a Martingale progression and we all know that will eventually clear out your bankroll. Unless for some inexplicable reason Card 3 doesn't lose much more than 6 in a row, but that is just silly.
I've ran it for a few days on Time Machine and it didn't hit too big a downswing but you can guarantee that when you go live you would take a big hit straightaway.
So at your own risk, I attach the trigger. You need to set your default back stake and then change the value of the user variable: start_back to your desired default back.
Less aggressive progressions like D'Alembert could minimise the heart attack risk.