Urgot's Purge wont proc Phase rush

its just a single spell cast that disarms you as long as its up, iirc. spells that hit multiple times dont proc multiple stacks of Electro/PR but should stack PtA and refresh Arcane comet where applicable

It is a bit interesting given that it stacks conq, but yeah, I'm pretty sure this is intended. Garen's e is the same way on the pbe, stacks conq but not phase rush.