We allow the jailbreakers to distribute their hacks and even sell them.

I understand that. The target market for those jailbreaks is outside Canada, so distribution of our product would be limited by foreign laws. Foreign buyers would be dissuaded by stuff like the DMCA.

It works for Canadians, but it wouldn't really affect anyone outside Canada. Given the size of our market, it would have a minimal effect on the sellers of locked products.

even if it’s just for John Deer farm equipment it’s a huge boon to consumers.

Canadian farmers who aren't part of supply management schemes are in rough shape. As much as it might help them, they aren't a large market, and (if John Deer cares) the sellers will probably use other monopolistic practices to discourage it.

Sure, Apple and Google will try to make this impossible...

Android app builders regularly complain that their apps are heavily pirated by alternate app stores in China. As far as I can tell, that hasn't really changed Google policy. If Google is willing to ignore an app market the size of China, I don't think there will be any real effect from Canada doing the same.

I like the idea behind the proposal, but unless it hurts US corporations, it seems like a small tweak to help Canadian consumers, rather than meaningful retaliation in a trade war.