Gleaning from multiple sources, I believe that the reason Canadians developed indirect MG fire techniques was because we were not wedded to any preconceived doctrines or military culture prior to the Great War, and most of the senior commanders on the Canadian side at that time stepped into the job from business and industry, so were more attuned to the idea of experimenting with their organizations to get the best effects.
ID with MGs is such a massively useful technique that once you come across it, it is hard to understand why you would NOT adopt it (but maybe that's me). OTOH, using MG's in the indirect role is a dying art, and hardly ever practiced on the range or on EX. When I announce to troops that the GPMG G-6 can be used to engage troops from over 2000m using a map and compass, they generally look at me like I just grew an extra head.
Of course, even suggesting that the SF kit should be with the MG at all times (even during the advance) elicits a similar reaction from most PL Comds and 2I/Cs, even though the firebase becomes vastly more effective once the guns are up on the tripods, the attack can be shot in with fire much closer to the advancing troops than when in the light role, and enemy counter attacks can be met at ranges of up to 1800m if ground and visibility permit.
To me, machine gun courses and training clearly needs to be rethought and gunners made very familier with the ID capabilities of their weapons (this isn't to difficult to do, there are several chapters in the GPMG pam and range tables to allow you to do this). OF course, I would also like to know that gunners are familier with the DF capabilities of their weapons. As a test, next time you go on a MG range or in the SAT, give the command "[range], [target indication] Traversing fire, from Left to Right, GO ON! and see what the gunners do...It probably won't be pretty.
