Photoshop allows us to start typing numbers and thus change the opacity for the selected layers. If we are fast enough, we can type something like '57' and Ps takes it as 57%. Pressing zero makes it 100%.

There is no way to disable this in Ps... and it doesn’t allow to use digits keys for any other command or a tool.

Ai allows to map digits just fine (and 1 and 2 are used for Quick Pen Tool currently), and it also allows to map keys to opacity values in Keyboard Shortcuts > Tools — although these are not as precise, and only allowed by settings tens: 10%, 20, 30...

I assigned several I personally need, like the screenshot attached shows, but perhaps someone needs to have it exactly like Ps does it? Please comment why the approach above is not enough for you.