In Ontario we've been using EPP since covid started, I'm hoping ACP makes it a permanent thing. We also required gps recordings of the ride because the insurance wanted it (dunno why), so that made it pretty easy to check that there wasn't any shortcutting... but in my 6 years I've never heard of anyone doing it here, at least on purpose, sometimes construction detours cut a couple km but most routes are over-distance by a few km anyway.
The roads in southern Ontario are mostly a grid so it's pretty easy to shortcut and I found trying to design routes that avoid potential shortcuts ends up making for worse routes because all the shortest routes happen to be the busier roads. Most people these days just seem to blindly follow the gps line and would only shortcut back to the start if they were abandoning. I couldn't imagine putting controls 10 miles apart unless there was a mountain in between them, but even then it seems kinda excessive.
There's a few routes in the east and the near-north where there are no 24 hour services but we make riders aware of it and highly recommend people don't ride through, but there's a 1000k that we've done twice and both times through-riders had to be rescued, once by the cops. Next time we do it there will be probably be a mandatory sleep stop, but generally in the south-west of the province you can ride through and probably find a 24h tim hortons or a circle k, though covid has cut down on that somewhat.