a progressive revenue system?the last step of tax?

In the future, we’ll have to design a progressive revenue system that relies more on personal income and consumption taxes, like the value- added tax, which also would help to increase our exports, because they escape the last step of tax, making our products more affordable in other markets.

What does the author mean by "a progressive revenue system"? Is it the same as a progressive tax system?
What does the author mean when he says the exports excape the last step of tax? What is "the last step of tax"?

Many thanks!