Understanding と勝手が違っていけねえや


> スカーフの下のレイドデバイスを外そうとして、後部箱型荷台の整備クルーから知覚同調で通信が入る。
>
> 『──ノウゼン少尉』
>
> 「伍長、無線のスイッチが入ったままだ」
>
> 知覚同調と無線の双方から同じ舌打ちが一つ。
>
> 『 **いけね** 、そうでした。どうもこの、知覚同調ってのは無線 **と勝手が違っていけねえ**
> や。何でじゃじゃ馬に加えてこれまでうちの隊で実験するんだか……と。弾薬の補充、また高速徹甲弾と成形炸薬弾が半々でいいっすよね』

86─エイティシックス─Ep.2 ─ラン・スルー・ザ・バトルフロント─〈上〉 安里アサト

What does the bold ていけねえ mean here? Does it mean the same as いけね? And what
does 勝手 mean here? The 勝手 seems redundant because it's already clear that the
伍長 thinks the radio is different from 知覚同調.




[いけない](https://dictionary.goo.ne.jp/word/en/%E3%81%84%E3%81%91%E3%81%AA%E3%81%84/#je-2990)
means _bad, wrong_. いけねえ is a colloquial variant and the first いけね is a light
exclamation similar to English _My bad_ or just _Oops_ meaning the speaker
made some mistake. いけね can be used only as an interjection.

知覚同調は無線と勝手が違っていけない literally means "知覚同調 is not good, being different from
radio communication in terms of
[勝手](https://dictionary.goo.ne.jp/word/en/%E5%8B%9D%E6%89%8B/#je-12857)". So
simply put, without 勝手 it sounds like "知覚同調 is categorically bad in contrast
to (good) radio communication".

勝手 is a word very hard to translate (as easily seen in the examples of the
definition linked above), but means something like _direction_ in a rather
abstract sense. In the particular sentence it means something along the lines
of "user experience", and the overall sentence says 知覚同調 is (at the moment)
not handy or harder to use since it is different from radio communication that
the speaker is used to.

