Dual boot Persistent Kali + BlackArch on USB?
I currently own a removable SSD USB stick with 128 GB available on it. It has a high enough read/write time that it maintains persistent Kali very well and is split into two partitions currently to accomodate for the persistence partition Kali requires to have a persistent boot as well as the partition that holds Kali itself. I already have a lot of data and installs on Kali that I would rather not wipe (but I can temporarily move stuff), but would like to install BlackArch alongside Kali on the same removable stick as a dualboot option. However, I have never setup dualboot before and have no idea how to do so, and am unexperienced with installing BlackArch and it only caught my attention after I worked with it on a friend's computer. How might I go about setting this up on my USB? I have plenty of space to do this, just am a little lost on how I'd go about it.