Two 96 hour visas? How would I arrange my second 96 hour visa and is there a minimum amount of time needed between applications?

(Canada)

As a Canadian, I need to prearrange a visa. I am flying Emirates and will go through their application process. However, I can only get a 96 hour tourist visa, single entry.

I wanted to stay overnight in Dubai both on my onward and my return flights. How would I arrange my second 96 hour visa and is there a minimum amount of time needed between applications?