This notation is absolute nonsense! The aim of a rhythmic notation is to convey and transfer a rhythmic idea that is readable and hopefully performable for the musicians and understandably for the audience.
We even don’t know what to count and where to place an accent, which notes are on or off beat.
If 1/8 is the beat a 15/8 time could be notated in 3x5/8 and then play it counting the 32nd notes (5 times one two three four = 1 bar of 5/8 and the underline or circle in the number where you have to play:
To make this process easier I propose to notate the value of 32nd above the rests!
I do just for the first note by bolding it ... the rest is up to you:
(1234 1234 1234 1234 1234 ( 5x1234 = 5/8 or 15*1234 = 15/8 for sado - masochists)
I also would suggest to double the note lengths for easier reading: 15/4 respectively 5/4 and transcribe it grouping them differently to find a sense.
Or just don’t notate it, as you can improvise anything that nobody can decode and understand but just have good feelings.
If you have problems with reading a rhythm try following steps: