In Ontario anyway, almost all workers are entitled to a minimum of 4% VP and two weeks off regardless if they are hourly or salary. There are a few exceptions that are mostly industry based. Also, in Ontario, the legislation is just 4% on earnings, not VP on VP. I have just come across one particular employer that is doing it this way, but I haven't found out why yet. It could be in a labour agreement, I don't know.

Maybe it's to top up the VP amount to catch wage increases. If SusieQ worked for $50K last year, but has a raise now and earns $60K, without the VP on VP, her VP available would be only 4% of the 50K, which is not her current salary rate. Of course, that would only work if the wage increase is in the neighbourhood of 4%...

 2 weeks salary or 4% on wages amounts to the same thing. 4% of 50 weeks is 2 weeks.

I don't know about the contiguous block in Ontario though. I think I'll watch for that. Good thought.