Collating the votes takes minutes. There is no physical meeting these days and votes are cast before the meeting time by fax and email.
How long it takes to get the results or discuss any proposed amendments depends upon who is dealing with the meeting (and whether there is a lunch break pending!)
My phone call came, as I recall, within an hour of the appointed time.
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014