Ajax Processing for numeric fields

Hi all,
Having the need to update a listbox when a numeric field changes and not having the Ajax Processing section available I was forced to use a Javascript workaround to obtain the result.
A simple question: why is this section not available on numeric fields while it is on text fields?
It would be extremely convenient.

As for the workaround I forced a “change” event on a supporting hidden Text field.

On my numeric field:
Event: onchange
    const seldep = document.getElementById("id_sc_field_dfrefresh");
    const event = new Event('change', { bubbles: true });
    seldep.dispatchEvent(event);