Explanation on how VAR_STRING aka 0xFA925AC00EB830B9 native works

Coming from an old version of the natives.h that still had CREATE_STRING, what is known about how VAR_STRING is used?

The first argument is a flag but all the comment says is that the first bit MUST NOT be set and that a value of 0 should be set when "passing a hash".
Does the first flag seem to influence anything else? is there a difference whether I pass 2, 10 or 0x7FFFFFFE ?

Followup question, if I want to pass a Hash, a hash of what exactly can I even pass to this function, and if I have a valid has, do I just pass it like VAR_STRING(0, myHash) ?

Next question: why the template arguments? can I provide more than 3 arguments? if so, what do the additional arguments even do?

From usage examples, I can see that the "second" argument (after the flag) is almost always just the hardcoded string "LITERAL_STRING". What other values are possible to specify here? I have seen "CASH_STRING" in one location, but are other values known

The "third" argument is then the char pointer to my (i suppose UTF-8) encoded string. so far so good.

But what about additional arguments? what if i provide a fourth or fifth character pointer?

I am asking because I am trying to display UTF-8 encoded korean characters that the game just displays as empty boxes. The characters are valid UTF-8, but as korean characters three bytes wide each. What surprises me that displaying cyrillic charactes is not a problem, these are also UTF-8 encoded and two bytes wide. So is there maybe an option or argument to enable additional characters for drawing strings?