Rules for にもかかわらず with な-adjectives

Question

Lately I've been looking up some entries in "A Dictionary of Intermediate Japanese Grammar". Under the entry for にもかかわらず (p. 257), it describes the formation rules for な-adjectives as:

(iii) Adj (na) stem {なの/である(の)} / だった(の) / であった(の)} にもかかわらず

Note 2 also says:

The verb (i.e. Vinf) and Adj(i)inf can be connected directly with ni mo kakawarazu, but Adj(na) has to be nominalized before it is connected with the conjunction, as shown by KS(D) and Ex.(h). However, if the Adj(na) is followed by de aru, use of the nominalizer no is optional.

Yet, under the entry for くせに on page 155, the book states under "Related Expressions" #2:

Ni mo kakawarazu expresses an idea similar to noni and kuse ni. However, ni mo kakawarazu is a highly formal and bookish expression and it expresses no emotion. Therefore, it cannot be used in highly emotive situations as in Ex.(g), (3), and (4). Note that the formation rules are different from those of kuse ni, as in [1].
[...]
(ii) {Adj(na)stem / N} {∅ / だった} にもかかわらず
Examples :
{不便 / 不便だった} にもかかわらず
{子供 / 子供だった} にもかかわらず

This seems to suggest that the stem of な-adjectives can be directly connected to にもかかわらず, even though the book itself contradicts this under the entry for the latter. So now I'm thoroughly confused. Is 不便にもかかわらず grammatically correct?

I also searched various web resources for the grammar rules, but many of them flatly state that you should add である to な-adjectives, which seems to be an oversimplification (according to ADoIJG at least...)

Answer 1

Adj(na) has to be nominalized before it is connected with the conjunction

If "nominalize" in this passage only refers to nominalization by の, this statement is indeed less accurate. Putting にもかかわらず directly after the na-adjective stem is actually grammatical.

As you may know, na-adjectives are just nouns followed by copula in their origin. Thus, stem of a na-adjective is syntactically a noun, and reverting it back to the bare stem is, in a sense, nominalization. However, in the meantime, they are semantically already adjectives as a whole, so the bare stem usually has no explicable "meaning" on its own (unlike the stem of suru-verbs can be used as verbal noun by itself). Its only practical role is being component of some expressions or compounds, one of which is にもかかわらず.

That being so, I still argue that ～なのにもかかわらず is felt more natural (flowing smoothly) as a native speaker. 不便にもかかわらず does not sound very bad, but it is perhaps because 不便 can be a noun "inconvenience" as well. I mentally try to parse what comes before にもかかわらず as noun by default. Using na-adjective stem directly sounds as if wearing an extra academic or journalistic flavor seeking terseness.

Answer 2

According to my textbook, 上級へのとびら, lesson 9, you can attach a noun (名詞) or a na-adjective (形容動詞) to にもかかわらず directly without である, being である also possible.

Quoting an example sentence from the grammar explanation in the book (note the brackets to denote "optional"):

彼女は外国人(である)にもかかわらず、日本人より日本の文化を愛している。

The book does not provide an example sentence with a na-adjective, but it does say that they conjugate like nouns for this grammar. In the book, the grammar is of "Type 3", which means that Nouns and adjectives connect to that grammar point with ∅ / だった / じゃない / じゃなかった:

As you can see at the third row (Type 3) of the second table where grammar connection types are shown, they use 不便 as an example, so 不便にもかかわらず should be possible.

I would say it is grammatically correct but of course your textbook note is pretty clear on the need for a nominalization and after all, it does not provide an example sentence with an actual na-adjective. In the end, I backed my answer using another textbook as a source, so take it with a grain of salt.