Where is that text from?
That is the most recent full text on the party’s immigration policy that I can find, it is from 2004.
They don’t elaborate anymore on some of their positions, for instance this is all they say about it on their platform.
3.4 Free Trade and Migration
We support the removal of governmental impediments to free trade. Political freedom and escape from tyranny demand that individuals not be unreasonably constrained by government in the crossing of political boundaries. Economic freedom demands the unrestricted movement of human as well as financial capital across national borders.