Building FW including add'l packages

I'm building my own FW including some add'l packages
I use the config.buildinfo so that to benefit later of the repo.
While I compile for one single target (WT3020) I still use the multi target option so that to include the DEVICE_PACKAGES listed in the related mt7620n make file
Everything works fine until I try to add additional packages to the device definition
Make menuconfig -> target Devices -> WT3020 -> additional packages
At this step it is possible to write the list of the desired packages I want to include for this particular device
Here is my list: usbutils kmod-usb-storage kmod-fs-vfat dosfstools blockd luci-app-ksmbd
Code generation is OK (no error)
What is surprising is that the generated code only incorporates some of the listed packages
from the above list only are included: kmod-usb-storage kmod-fs-vfat blockd
The following packages are missing: usbutils dosfstools luci-app-ksmbd
Can you help me to understand what I'm doing wrong.

DEVICE_PACKAGES are only added to a clean build configuration (symbol not deselected already) and are skipped silently, if unavailable from the current build, make sure to account for that.

It's best to maintain a tiny/ minified seed config (see e.g. hnyman's builds) and to expand them using make defconfig, at that point the DEVICE_PACKAGES will be selected (if their dependencies can be met) automatically. Another approach would be to explicitly enabled the necessary packages as =m in addition to the DEVICE_PACKAGES, as failures would be flagged that way.

(Personally I'd prefer the former)

These are not "DEVICE_PACKAGES" but "PACKAGES".