Seems to be good luck rather than good management when it comes back promptly.
Most of the CASA doctors are part time, and only there a couple of days a week. So if they request further information after your medical, it can take some time for them to review it.
Last time I called them to follow up on some info I had sent, I was told they had
28 business days to respond to correspondence! Gee thanks!
You can do your medical up to 28 days before the expiry date, which I do. That gives me 28 days + 2 months to get it sorted. (Assuming your DAME doesn't ground you on the spot.
)
Last one took 10 weeks. Appalling service.