https://m.dpreview.com/reviews/olympus-om-d-e-m10-mark-iv-initial-review/3

The only customizations you can apply are for the AE/AF Lock, video record and digital teleconverter buttons, and even then, there aren't many choices available.

すげぇな、ダイアルのカスタム割り当て不可な上にボタンの割り当ても大きく制限されてるとさ
mark iiiより更に劣化させてどうすんだよ