Are infinitival verbs, verbs or nouns?

Infinitive verbs should always be treated as verbs, even when they have nominal modifiers

The UD documentation states

Note that some verb forms such as gerunds and infinitives may share properties and usage of nouns and verbs. Depending on language and context, they may be classified as either VERB or NOUN.

We, therefore, need to determine when these will be treated as verbs and when they will be nouns. Originally, we were operating under the principle that if an infinitive verb was modified by nominal modifiers, it should be marked "NOUN" with "VERB" being the default. However, there are numerous cases where the infinitival has both nominal modifiers and elements in the verbal subcategorization frame (e.g. objects; subjects are illicit).

Because the verbal morphological features cannot be (validly) represented on nouns, all infinitives/gerunds are verbs.