I'm currently processing film with inversions at 1 minute intervals, however I'm going to be looking at 3 and 5 minutes intervals for some film/developer combinations. So I would really be interested in the 30 second beeps being variable: either from a predefined list (15 sec, 30 sec, 1 min, 3 min, 5 min) or infinitely variable within specific parameters. I personally think this would make this timer indispensable as it is something that I cannot do with a normal kitchen timer and it would mean that I'm less likely to inadvertently perform an inversion at the wrong time.

Can you confirm that the end of process sound is different to the 30 second beep?