Here in BC I’ve never heard of any other coaching process other than Equine Canada. It gets you much reduced insurance rates. I’ve also never heard of anyone doing a rider level test other than for their initial certification to coach. I haven’t even heard of kids taking them. We do have Pony Club and I have a general idea of their levels but I am not involved.
When people are getting certified as coaches they just do the relevant rider level test, they don’t do the whole series. Years ago I watched a young woman acquaintance try it and fail, which was interesting. It did strike me at the time that it weeded out the wannabe young adult coaches whose riding was a bit rough. I can’t remember if it was level 6 or 8.