Yeah, I've heard all the horror stories as well about removal from fellow Z owners who have attempted it. In fact, I had already made an appointment for my dealer to remove it because I had resigned myself to not tackling removal myself due to all those reports for fear of damage. Anyway, I got curious (and lucky it seems) before my appointment to give it a try using a rubber strap wrench with a microfiber towel in-between it and knob as a buffer. Surprisingly the factory knob came off for me with just a moderate amount of force, and with zero damage (as shown in OP pics).
No need to, thankfully. I did order Billetworkz aluminum boot retainer along with the CHONK, but because of the way the CHONK is design with large opening in bottom it allowed the OEM boot trim to mate perfectly with it inserting inside after just a slight modification to its inner threads, so the Billetworkz retainer was not needed. I added a few more photos to OP to help show how all that goes together.
What was the slight mod to threads you made?