There’s a longstanding error in Digi’s busybox bbappend, where it’s examining the defconfig for enabled features, rather than live (patched) .config file.
This means that, for example, it’s impossible to disable the HTTPD feature properly via the config file in a layer.
I’m not sure if/how a layer can modify the actual bbappend file of another layer to correct issues such as this?
This issue remains in the latest DEY 3.2 release.
That is something that you should email Digi Support about or open a support case about.