Tornado Technologies will thread a barrel. They threaded a Rami barrel for me and it works just fine. I'll send a Kadet2 barrel to them to thread after I break it in for a month or two. According to their website they offer a Kadet Kit with an already threaded barrel when kits are available!
https://www.tornado-technologies.com/product/CZ__0010/CZ-75-KADET-threading-service/
Well, this bit of advice from August 2021 came back to bite me...but all has ended well.
I sent off my Kadet 2 upper and barrel to Tornado Technologies back in May 2022. Shortly after that it appeared they went out of business. Bounced email's, no phone calls answered, etc. Saw tons of angry posts on their facebook page. I figured it was never to be seen again.
In April of 2023 I got a shipment notice from UPS that my threaded barrel was completed. Time came and went, and the package never showed as actually being shipped.
Out of the blue today, UPS delivered a box from Tornado Technologies. Yes, it was my threaded barrel and upper finally being delivered to me. Yea!!!
Sorry, to anyone that took my advice and used them. I did have very good luck with them on my threaded Rami barrels before the Kaded 2 incident.