Do Negative Downstepped i-adj's have accents on な?

Question

Consider that 上手い is a downstepped i-adj (i.e., pronounced as うまい{LHL}).

Question: What are the pitch accents of the following negative conjugations of 上手い?

• 上手くない
• 上手くなかった
• 上手くなくて
• 上手くなければ
• 上手くなる (not a negative conjugation but Dogen includes this with the others; see below).

According to OJAD: no accents on な's

According to OJAD, they're all accented on the first mora, with no accents on な:

OJAD also has a "word conjugation table" page, which shows an additionally correct pitch with accent on their second mora (but again no accents on the な):

According to Dogen: additional accents are on な:

According to Dogen's pitch accent course, the rule for determining the pitch of negative i-adj is to conjugate the i-adj into its く-form, and then add ない{HL}, なかった{HLLL}, なくて{HLL},なければ{HLLL}, なる{HL}. Notice that in all of these cases, accents are on the な. This leads to the following:

So which is correct? Are they both correct?

Answer 1

According to 日本語アクセント入門, for non-Heiban (起伏型) words, there is a second downstep at な. That is, there is not a rise before な, it just goes down. In this sense, both are not exactly correct (OJAD doesn't show the down step (clearly) and the video shows a non/hardly-existent rise).

p37. (adapted) 起伏型のナル形(ヨワクナル)は、.... 語句の頭のヨのところで下がり目が生じた後、接尾辞ナルの第１拍目の後ろで2度目の下降が生じている。このようなピッチパターンを図にしてみると、次のようになる。

ヨ'

　　　ワク ナ'

　　　　　　　ル

１つのアクセント単位の中に２つ以上の下降が生じた場合は、このテキストでは、1回の下降ごとに ] という記号をつけ、例えば[ヨ]ワクナ]ルのように示すことがある（[は急激な上昇を示す）。

This applies to other suffixes. The same book (p39) has

辛い　[カ]ラクナ]イ　
怖い　[コ]ワクナ]イ
弱い　[ヨ]ワクナ]イ
強い　[ツ]ヨクナ]イ

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I guess it depends on how much 'independence' is felt before ない (or other prefixes). If there is a complete rise before な, it does not sound like a suffix, but still ない IS perceived as independent to some extent, hence the down stepping.