.......... I know that some times good teachers use every tool in their disposal to push their students - even flattery ..........
Ah, Antonios, you have exposed my devious ways!
But I am sincere about recruiting your considerable skills.
.......... Please do also post your examplar of copperplate - I remember you posted one that you wrote with an Osmiroid Copperplate (an interesting nib, by the way) ..........
Yes, I will do that tomorrow when my server comes back up.
I am posting below practical advice for nib flexing "needed" for copperplate. If I would write it again, I would change the title because flexing to the max is not what copperplate is. The advice below is how to get the tine opening you want with minimum stress on the nib. It comes from my experience as a mechanical engineer rather than as an expert calligrapher.
I was fishing for you to do this, Antonios, for I think your explanation and analysis of the process is excellent.