Doesn't remove aluminum so it doesn't leach it back into tank. But you're correct. There is a debate on whether it releases aluminum. Highly debated, and so many variables it's impossible to conclude that it's marinepur, or if it is, that it raises levels hi enough to have an ill effect on the tank. The one thing that does seem clear is that if it's in a low flow area, and hasn't been cleaned regularly, that spots with low enough oxygen are the cause.
Either way, if you're spending the money to do triton than you don't need the marinepur, but you already spent the money on the marinepur. If there's one thing in this hobby I've learned, it's that slow and steady wins the race. Keep changing things around and you never find success, or nail down what works, and most times create more problems than you solve.