I chose to write them in this manner to imply that those 32nd notes should be played a little lighter than the others, while not being ghost note either.
Grace notes could be used to achieve almost the same result, depending on the tempo, but they're meant not to have a rhythmic value, so I guess they would make it a little more difficult to understand.
I just checked it out, very cool exercise indeed I have to say ! Thanks for sharing, Alain!
Concerning the smaller notes: The idea works, but I also tried the opposite, as in a "normal"
herta the thing that sounds cool and makes the herta stand out is actually accentuating the
32nd notes, isn't it?
And I also played the same patterns thinking in 4/4, which has a nice effect too.
Glad that you like the exercise, thanks!
I'm not sure what a "normal" herta is, but I think it's better to not overplay the 32nd notes. It is also cool to try different options.
I'm writing a whole book based on what inspired this exercise, and there's a whole section on ways to play this in 4/4 as well.
It's going to be more than one book actually.