Thank you very much Christian, I really appreciate your advice and tips 
I think it’s like you say, these things are very specific to a persons built, training and response to diet. On top of this, like you say, a measurement by one coach @10% isn’t necessarily a true 10%.
So summing it up for me, I think I’ll just try to diet down further until I see a full six pack (which was what I wanted to begin with). I’m now only seeing the top two rows, so I still have a bit of work to do. When I then finally reach the full sixh pack, which will probably be around 8%, I can start building muscle by lean bulking between 8% and 12% at a maximum. I guess a 4% range is ideal.
My current coach does the adjustments to the diet gradually. Each month only a difference of a 100 calories up or down. I guess that’s why it takes such a long time to get from 10% to 8% and it’s not done in 4 weeks. Of course, I could always ask to be a bit more drastically and use increments/decrements of 250 calories at a time.
Bur first things first, getting to the 8% and finally see a full six pack would make me happy. So let’s go for that 
Thanks again! It’s really great being able to ask a question to a true professional.
Have a nice day 