Kali? R-01? You’ve gotta be kidding me.
Running Kali that way, if such an endeavor exists, is an exercise in patience. But if your scope is about similar to a Flipper Zero…, still, why?
That leaves you to choosing between A-06 and the CM4. The A-06 is pretty much as good as other Raspberry Pi alternatives out there, which is bad. Hate to disparage Clockwork here, but the CM4 is where all the action (and the good stuff) is.
And then we go to Kali itself. You do have two options here. One is to assemble it the official way. The other has more recent updates (and driver fixes) provided by a fellow user here. As much as I understood it, neither images come with Kali’s kernel patches, so some tools may not work properly. And even then, you need peripherals to make some tools work; they may not work with the built-in hardware.
Ultimately, none of the CPU options are speed demons. You can see the Geekbench result for the CM4 yourself here. You’d probably be prosecuted by the court before somehow successfully cracking your neighbor’s Wi-Fi. (I exaggerate.)
So, yeah. That’s about as much stuff I can gather about why not to run Kali on a uConsole. You’re welcome to try anyway. This is just a caveat emptor.