Thank you for those precious steps on how to swap a kernel version in an 
ISO!
It will sure prove valuable to some people in the future. I wish I had 
known how to do that a month ago in order to install ascii on a Dell 
Latitude 7400, which Intel network chipset was not handled by the 
shipped kernel.
Had to do buster -> beowulf (had not put my hand on any beowulf ISO), 
and... and due to some more difficulties, had to start from a minimal 
buster which proved problematic in the end :oD
Glad to read you're joining us, and glad to read you're here to stay!
Bernard Rosset
https://rosset.net/