negative toward, happy about - prepositional phrases or idioms?

Comments [that are] negative toward the candidate are being deleted without notice.

The underlined is a reduced relative clause.

If so, the rule about unable to directly reduce pronoun + verb only applies when the adjective cannot stand on its own?

The rule in application: Ex. "The man who is angry is outside" cannot be reduced to "the man angry is outside." Instead it has to be "the angry man is outside."

Thanks in advance.

Nevertheless, it has been done above.

Meaning we can reduce a relative clause even when there is an adjective? (both grammatically and academically safe as well?).

Various sites state that a relative clause cannot be directly reduced when there is an adjective:

"The man who is angry is outside" cannot be "the man angry is outside." Instead it should be "the angry man is outside."

However, we see sentences like the below:

People angry about the latest political scandal are protesting outside.
Comments negative toward the candi

You can here: Comments that are negative toward the candidate are being deleted without notice.

But you cannot here: The man who is angry is outside.

Thank you.