Also I suggest you read the youtube video description, some great thoughts about diabolo shared there!
I notice that Guillaume is doing 4 diabolos in 53 pattern ( 5 on the air, 3 on the string = 53F ), and he do 6 diabolos in 93 pattern ( 9 on the air, 3 on the string = 93F ).
Do you mean the diabolo sliding on the string is a 3 and the diabolo in the air a 5 in this 4 diabolo sideswap pattern?
but I never thought about the diabolo which is on the string going from the right side to the left because you don't throw it
(which would be a 4 in normal known diabolo sideswaps)
If that is what you mean, that is a really interesting idea. Even though I don't know what that would be useful for because that's normally how a Low Pattern is always like.