I have a QM Verona, I initially tried the two hole tip sans plastic liner in wand. I found it fine for steaming milk for one drink but far too slow for more, and changed to 4 hole tip.
I did find initially that it was difficult to control, (milk for 2 drinks) went back to 2 hole but quickly reverted back to 4 hole tip, it requires perseverance to perfect using the 4 hole for small quantities of milk (two drinks) but it is definitely worth the effort. When steaming larger volumes of milk it is absolutely perfect and speedy.
The steam valve on the Verona does not act quite like a water tap , after an initial graduated opening it progresses to considerable volume /force.
With reference to the hole in tip angles,in the 2 and 4 hole they are angled out at 50 deg in both (each hole)
From these angles it can be seen that if the wand is applied centrally to the "jug" pitcher the steam will push the milk down and out towards the bottom /sides and roll the milk up the sides.
If the wand is angled across the pitcher and to the side this will induce the milk to spin.