ならともかく

JLPT Level: N2
Meanings

If it's A, fine, but B is the issue

Setting aside A, focus on B

A may be acceptable, but B matters more

Usage

[A] ならともかく [B]

Noun + ならともかく + [B]

Clause (plain form) + ならともかく + [B]

Explanation
ならともかく is used to acknowledge that one thing (A) is acceptable or less problematic, while indicating that another thing (B) is more important, problematic, or deserves attention. It often introduces a contrast where the speaker wants to set aside A and discuss or criticize B. This pattern is common in everyday conversation when comparing two aspects of a situation, opinions, or decisions. Note that the A part can be a noun or a clause in plain form; the B part is what the speaker emphasizes or critiques.
外観は立派だ。使い勝手ならともかく、耐久性が心配だ。
がいかんはりっぱだ。つかいがってならともかく、たいきゅうせいがしんぱいだ。

The exterior looks impressive. Setting aside how easy it is to use, I'm worried about durability.

友人は親切だ。話し方ならともかく、約束を守ってくれない。
ゆうじんはしんせつだ。はなしかたならともかく、やくそくをまもってくれない。

My friend is kind. Put aside how they speak, they don’t keep their promises.

この機械は安い。操作性ならともかく、説明書が分かりにくい。
このきかいはやすい。そうさせいならともかく、せつめいしょがわかりにくい。

This device is cheap. Setting aside how easy it is to operate, the manual is hard to understand.