Here's what you're running up against: Most modern drives do not allow you to format at anything other than 1:1 interleave. So, HD SC Setup can make all of the requests it wants, but the drive's own controller will blithely ignore all requests to format at other than 1:1 interleave.
I'm actually amazed that you were able to get the Plus to boot off of a 4GB drive! That is a *very* rare achievement.

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It seems that you get the right answer : the disk drives do not accept the interleave = 1 option, as lesat as far as HD SC setup is concerned.

I will try to use others formatting software to check out if I can solve this problem.

I agree with you : I do not understand why this 4,2 GB HD is able to boot with my Mac Plus. The driver is register as ".ASC00" that seems to be the Apple HD SC setup one, and the interleave factor is 1 !