So have you actually managed to make some money by doing this? I must admit that this looks very complicated and time consuming.
The majority of the arbitrage today have been done by the arbitrage bots. I am sure that these bots can be coded to trade these triangular arbitrage as well. This would be much easier to do than to do it manually as you suggested.
It is indeed complicated and OP is exaggerating when he says that it's a zero risk profit.