Call ads while intake is staffed, form ads for the overnight readers
Split the account by when a human can answer, before you split it by anything else.
An immigration inquiry at ten at night is real. The person is awake because they are worried. A call ad pointed at a voicemail box at that hour spends money and produces an unreturned message, which is worse than no ad at all.
Run call extensions and call campaigns only during the hours the phone gets answered by somebody who can book an appointment. Outside those hours, push the same budget to a short form that promises a callback in a stated window and then honors it.
Segmenting this way also gives you cleaner data. Daytime call performance and overnight form performance are two different funnels, and averaging them makes both look mediocre.
Do the same with days. Weekend inquiries from shift workers are common and most firms have nobody assigned to them. Decide whether you want them before you buy them.