In my opinion, if a renter moves into a no smoking/no pets building they would be expected to live by those standards. Fact is though, even in buildings like this, folks may and do have cats and dogs.
I think having a cat or dog would be much easier to prove by someone, than I think my neighbour is
vaping, good luck proving that in a court of law.
Your landlord probably wants to have a no smoking building overall, to attract more non-smoking tenants,
a lot of folks hate the smell of smoke so this is a selling point.
Whether vapes and cigs are grouped together as far as the law goes I can't say, it seems to be a regional or a town bylaw that you'll have to look into.
Even if you are sitting on a balcony puffing clouds and you are spotted you may still be within your rights as you are not inside.
It is very, very difficult to have a tenant evicted, it sounds like you are a good tenant, I doubt your landlord has this in mind by changing the lease details. He is doing it to make the place more attractive to non-smoking tenant$. imo. Cheers.