This subject has long been a sore spot with me - even more so since .ca came into existance. While I can understand .com's reluctance to add leaf categories for non-US makers, there is no reason in the world that when listing Canadian items on .ca we don't have appropriate categories to use.
The one that affects me most is in pottery. There is a category for Blue Mountain Pottery - but that is the only Canadian company represented. If the other makers don't rate a break out of their own (by whatever criteria ebay uses), then the least we should have is an additional Canadian Pottery sub. It is unfortunate that because of this oversight on ebay's part, Blue Mountain has become almost a generic term for any redware made in Canada. This fact has lead to much abuse by sellers and a devaluation of many of the other potteries.
Another ridiculous oversight is in silver - Birks, world famous Canadian silver maker is not represented so when I list Birks sterling on .ca I don't have a proper place for it. Silver > sterling > flatware > final list is American makers, so I have to pick "other makers". The alternative is to go from silver to sterling to NON-US. This is on ebay.ca !!!!
Lets move to glass. Have some great antique Canadian pattern, flint or pressed glass? Well, if you choose glassware then you get moved along to a list of American makers and have to use EAPG or other. Try another route and go for art glass > North American > list is all American makers - not a Canuck name in site, not even just "Canadian".
I'm sure there are lots more examples of where we need Canadian specific sub or leaf categories on .ca - sellers of different types of items likely have suggestions worth persuing. I have only brought up these 3 because I regularly list in those areas.
Post your "needed" specific to Canada requests and we can use the info to write ebay and make the requests. I have been asking for "Canadian pottery" since day one, but requests from a large number might get some attention.