hehe No. I did not test any other interleaving factor. The theoretically optimal was 3, but it was a bit too close, so 4 should be better. I really have to test, but in any case the speed now is nearly the one in the emulator, which is great!
Also I did not test the floppybuilder version you posted... I have version 1.001 what are the changes?
We also could talk about the changes in the loading and loader code, because it is now cleaner and supports Telestrat (does not boot, but works) and Jasmin, but they need some cleaning, normalizing. You can see the changes I made in the Blake'7 sources in the repository.
I have asked Fabrice about the possibility of adding an option to writedsk2 so it formats each track before writing. I really think that should be the default behavior.
EDIT: Just tested and it seems to work, produces a correct disk (tested on the emulator) with the correct interleaving (checked with an hex editor)
Anything else I should check?