the point i am making: if the major players don't use Gann's square, and millions more retail traders don't, you will need to add another filter to your chart to decide the actual quality of a Gann line and whether or not it actually defines a valid level you can trade against, because more likely than not, when price will stop at 1 of the lines, it is going to be due to coincidence more than anything else. just like when price stops at the 50% fib retrace and reverse, and the next time on the same instrument, it stops at 61.8% and retraces! so which fib to choose to trade against? what if PA (price action) seems to show it will reverse at 50% but then turns and crosses 50% because it was a fake move? and then people get stopped out when their SL put above the 61.8% gets hit and price reverses, and so on. it also depends on the TF etc... but in general, i don't use fibs anymore. nor MAs.
so i always say: as traders we need to find a universal invariant.
anyway, good luck.