>> Do you agree with this change?
>
> Yes, with the minor remarks:
>
>> +  The option @code{async-shell-command-width} defines the number of display
>> +columns available for output of asynchronous or remote shell commands.
>
> Do not mention remote.
>
>> +*** 'async-shell-command-width' defines the number of display columns
>>  available for output of asynchronous or remote shell commands.
>
> dito.
>
>> +(defcustom async-shell-command-width nil
>> +  "Number of display columns available for asynchronous/remote shell command.
>
> dito.
>
>> +      ;; Test `async-shell-command-width' of `async-shell-command'.
>
> `async-shell-command' shouldn't be mentioned anymore, it's obvious.

I hope now it's right: