It seems natural to me that something could be "considered as a [noun]" or "considered [adjective]", but trying to find some examples I found ones both confirming my assumptions as well as a few that seem to deny it:
The following payments shall be considered as ‘very critical’ and the [insert name of CB] shall use best efforts to process [...] them in contingency situations
[...] quotas for bananas pursuant to this Regulation should be considered initially as non-critical within the meaning of Article 308c of Regulation (EEC) [...]
- Is there some other rule in action here, e.g. putting the adjective in quotes requires the additional article?
- Or is the article simply optional here?
- Or are these examples wrong?
- Finally, should there be an article in the following sentence:
We have 21 comments, none of them considered as critical.