Maybe the M600 is a totally different beast from the 605 which I have. When I did the old Agfa MCP( not the Adox one) at 20x25 cms using a dichroic head for dual filtration my times were nowhere near these. Probably not even as much as Molli's times. Probably around 20 secs max but more like mid teens and this was the 100W halogen bulb

You are getting about 60 secs for a 20 x 25 which is not a big print and over 4 mins with the other paper. Seems incredible compared to my experience but if the prints look right then no issue. Your dodging and burning can be relaxed