The phrase "actually functions as a" is correct and usable in written English.
You can use it when explaining the role or purpose of something in a specific context.
Example: "In this experiment, the chemical compound actually functions as a catalyst, speeding up the reaction without being consumed."
Alternatives: "serves as a" or "acts as a".
"A workers council is absolutely necessary, if it actually functions as a council for the welfare of the company.
A connected spherical cavity, forming what is called a band-pass filter, actually functions as a type of band absorber or notch filter, removing a band of frequencies around the resonant frequency of the cavity (see below, Standing waves: The Helmholtz resonator).
You may end up having a dispute (or at least correspondence or discussions) about which of the "original" returns is valid, and whether an amended return actually functions as a superseding one.
Tally is unique in that it not only provides a way to organize and manage your credit cards: it actually functions as a line of credit itself (if you qualify).
Race as it actually functions, as a tool of human insidiousness and despotism, became real beyond my imagined utopia.
And yet there are financial issues - like the $304 parking ticket I recently received (because such draconian punishment actually functions as a regressive tax) - that are so emotionally charged that I will lose sleep for days over them.
In each one of her recollections, I got the impression that the HR department actually functions as an ally to the candidate.
Therefore, the most abundant spliced RNA, E6*I, actually functions as an E7 mRNA for efficient E7 translation.
Millgram (1998) argues that knowledge of the way such desires-at-will were brought about makes it impossible that they actually function as the desires they are intended to be.
What if the coffee joke actually functioned as a joke?
While they might look like apartment complexes, termite mounds actually function as a ventilation system for the colony that lives deep underground.
