The role of the alien in Identified reminds me: the TV episodes and
the Countdown / TV Action comic strip stories sometimes treat aliens
differently:-
In the TV episodes aliens never talk (except for one inarticulate
noise in Identified).
In the comics, some aliens talk, some aliens have names (Sagum,
Brobat, Robart), and at least two stories have scenes set on the
alien homeworld.
http://www.buckrogers.demon.co.uk/ufo/is.htm is a
summary of the comic stories.
Which would you prefer in stories? Given that Gerry Anderson's studio
only had two alien spacesuits available, but comic strip artists
aren't limited to what film props are available and can easily draw
on paper large squads of aliens and who and what they like which it
would cost a film studio a fortune to make and even more so before
CGI was heard of.