She is the actress that appears in (at least) 3 movies:
In
Illegal Entry (1997) -

In
Beware of Stealing (1998) -


In
Code of Passion (1999) -

In all of them she has a leading role, so likely that her name will appear in credits (even if they are very poor like in most of Taiwanese adult movies).
Acting credits from these movies (underlined names are identified):
"Illegal Entry" - ???, ???,
???, ??,
??,
???,
???"Beware of Stealing" - ???, ??,
??(??), ???,
??? (???)"Code of Passion" - ???, ??, ???, ???,
???, ??
that means, her name should be among these:
"Illegal Entry" - ???, ???, ??
"Beware of Stealing" - ???, ??, ???
"Code of Passion" - ???, ??, ???, ???, ??
While checking the names from "Illegal entry" she was found on Facebook by the name ??? -
https://www.facebook.com/profile.php?id=100002357838190So her name is ??? (Wang Wan-Xun). But this name doesn't appear in credits of "Beware of Stealing" or "Code of Passion".
In "Beware of Stealing" there are only 5 acting credits, and the story is about 5 people who live in countryside and have sexual relationship with each other.
Judging by the names of the unknowns, ??? is probably a guy's name, ?? and ??? are girl's names.
In "Code of passion" the name ??? is first billed, it is almost the same as ?? from "Beware of stealing" and Wang Wan-Xun has the first leading role.
Also, to less the options, I'm almost sure, who are ??? (from "Beware of stealing") and ??? (from "Code of passion") - still checking though.
Also, except Guo Shuang-Yi, who has one of the leading roles in "Beware of stealing" and a very small part in "Illegal entry" (probably uncredited), Wang Wan-Xun is the only person who appears in all 3 movies (especially in "Beware of stealing" and "Code of passion")
That means that ??? aka ?? should be an alias for Wang Wan-Xun, or maybe her previous name. Remember, that people in Taiwan are known for changing their names.
Here are cast images for all 3 movies (click to view bigger):
Illegal Entry (1997):

Beware of Stealing (1998):

Code of Passion (1999):
