I used to live in Florida and amazingly enough the homestead exemption works pretty well. I'm sure there are some people abusing it, but it's effective overall. You can only have it on one home and it doesn't apply to businesses so the only real fraud angle would be to live out of state and take the exemption on a single Florida property. You have to be a citizen or permanent alien resident which weeds out foreign buyers looking to park money. You'll also need to be able to access its mailbox, be registered to vote at the address, etc etc. A lot of potential legal trouble for a $50,000 valuation haircut on your tax bill.
The fact that Florida has no state income tax is an even bigger incentive to actually reside in Florida if you have a lot of passive income coming your way.
You can purchase Canadian permanent residency for $800,000 through Quebec's Immigrant Investor Program. This has a big impact on Canadian tax policy because there is no way you can discriminate between foreign and domestic ownership - foreign investors can simply buy a PR card and avoid punitive taxation of foreigners. There are still foreigners in the normative sense of the word, as in they don't and have never lived in Canada, but in the eyes of the law, they are the same as an permanent immigrant.
You can require presence in the country to a homestead exemption. If you aren't in the country for a large amount of time (say, 180 days) you don't get your exemption. Between that and having it only apply to a single property the incentives to park cash in an empty Vancouver apartment are diminished.
The fact that Florida has no state income tax is an even bigger incentive to actually reside in Florida if you have a lot of passive income coming your way.