Pretty sure it can mount to a mounting plate if you have one BTA on the cockpit, or install one through another mechanism.

Zipties work fine for me though.

I have the profile design aerodrink bracket but I am not sure if I can use it with the z4 cage...

The have top cap mount that I use. It can also be used for other bta

https://www.amazon.com/...-Mount/dp/B008BWMRFA

It's not great and rotates around when I forget to check if it is tight, but it's the best solution for me without switching to another system like those vertical bta