have been / are

(1) "The objective of this essay is to illuminate an aspect of early Communist rule in Poland whose ephemeral moments [have been] prone to being overshadowed by later events."

(2) "The objective of this essay is to illuminate an aspect of early Communist rule in Poland whose ephemeral moments [are] prone to being overshadowed by later events."

(3) "The objective of this essay is to illuminate an aspect of early Communist rule in Poland whose ephemeral moments [were] prone to being overshadowed by later events."

What difference would it make to the implied meaning of the sentence whether I use [have been] or [are] or [were]? My attempt:

In sentence (1) the implied meaning is that historically, ever since the early period of Communist rule in Poland, people [commentators, scholars, everyone etc.] have always tended to overlook this 'aspect' of it.

In sentence (2) the implied meaning is that people nowadays tend to overlook this aspect of early Communist rule in Poland but that in the past [the period between then and now] people did not.

In sentence (3) the implied meaning is that people tended to overlook this aspect of early Communist rule in Poland in the past but people nowadays no longer overlook it.

Is this how I should grasp the difference in implied meanings between the three sentences? So all three sentences are equally grammatically tenable, only that they have different implied meanings?

Thank you.
SuperESL