Hi @gvellet
I just want to follow up our thread with the below information!
We just released MCUXpresso Secure Provisioning Tool v25. I believe the tool provides security settings for the MCX C that you could find really useful. Below an ilustrative image, where I changed the MCU Life cycle from Unsecure to Flash secure.

As you can see in the BCA/FCF settings, the FSEC setting enabled according to Flash secured life cycle.
The SPT, for short. creates bootable and secure images, you can provide a sample image for the MCX C or your custom image. The tool requires connection to the MCU over USB/UART.
For more details about the SPT use, please refer to sections:
6.10 MCX C041/C242/C444 device workflow
6.10.3.3 Life cycle for MCX C041/C242/C444 devices
of the MCUXSPTUG , you can get it easily by doing this:

We can conclude that you can manually edit flash security settings for the MCU using the MCUXpresso IDE, however, we leveraged this to the MCUXpresso Secure Provisioining Tool
hope this helps you,
Diego