In a thread named "gerund or participle," CalifJim gave this as part of his answer:

For a participle, think adjective, think -ing (present participle) or -ed or -en or -n (past participle).
For a gerund, think noun; think -ing.

a thundering voice. (adjective, present participle)
a closed door (adjective, past participle)
a hidden motive (adjective, past participle)

I think we all can see there are three participles used as before-noun adjectives. When we use participle before nouns like them, the can we safely assume teh participles used can be (should be??) adjectives in a predicate position (most likely after a "be" verb??)?

appear thundering ...
is closed
is hidden

Can we use normal participle with the pattern of "has/had been + participle" as "before-noun" adjectives like above?
Anonymouscan we safely assume [the] participles used can be ... adjectives in a predicate position
No. You can't safely assume much of anything where English grammar is concerned! Emotion: smile
appear thundering doesn't work, for example.
Most of them do work as you say, however.
is closed and is hidden are both possible as a linking verb with a participle as an adjective. But then, they are also possible as verb phrases as well.
The tense of the linking verb makes no difference, so has/had been closed/hidden follows the same principles.