I think that ISOs are not so concerned about backdooring these days. They want real offers, competitive offers, and a funder who will pull through and fund, wire out commissions same day.
Especially the professional and talented ISOs that fund real numbers. Try backdooring them and see what happens (won’t be pretty). So instead of selling the “we don’t backdoor” pitch, you’ll need to actually sell the product you have. Which based on your words isn’t very strong.