Warnings when building with sysbuild to enable DFU over BLE (CONFIG_DISABLE_FLASH_PATCH, mcuboot flags)

Hi,

I have a BLE application where I want to use the device firmware updates (DFU) over Bluetooth. I followed the nRF Connect SDK Intermediate tutorial on how to enable the DFU. However, I got some warnings and errors along the way that I cannot resolve and also do not completely understand.

First warning:

When I try to add the CONFIG_DISABLE_FLASH_PATCH flag to my prj.conf file as stated in this post (post2), it throws that the NCS_SAMPLE_MCUMGR_BT_OTA_DFU has the value "n":

When I try to add the BOOTLOADER_MCUBOOT to my prj.conf it suddenly activates the old build process with child and parent image functionality. 

What is correct approach here?

The second thing is that I want to add these flags to the mcuboot, but with sysbuid it does not recognise them: 

The error:

How do I pass the correct the flags to mcuboot.conf?

Thanks for the help!!!