In arch/x86/Kconfig of the kernel tree it says for CMDLINE:
<span style="color:#323232;"> Enter arguments here that should be compiled into the kernel
</span><span style="color:#323232;"> image and used at boot time. If the boot loader provides a
</span><span style="color:#323232;"> command line at boot time, it is appended to this string to
</span><span style="color:#323232;"> form the full kernel command line, when the system boots.
</span><span style="color:#323232;">
</span><span style="color:#323232;"> However, you can use the CONFIG_CMDLINE_OVERRIDE option to
</span><span style="color:#323232;"> change this behavior.
</span><span style="color:#323232;">
</span><span style="color:#323232;"> In most cases, the command line (whether built-in or provided
</span><span style="color:#323232;"> by the boot loader) should specify the device for the root
</span><span style="color:#323232;"> file system.
</span>
and for CMDLINE_OVERRIDE:
<span style="color:#323232;"> Set this option to 'Y' to have the kernel ignore the boot loader
</span><span style="color:#323232;"> command line, and use ONLY the built-in command line.
</span><span style="color:#323232;">
</span><span style="color:#323232;"> This is used to work around broken boot loaders. This should
</span><span style="color:#323232;"> be set to 'N' under normal conditions.
</span>
So both commandlines will probably be used. I don’t think an initramfs will normally interfere with the kernel commandline. In any case you can make sure you got what you wanted with cat /proc/cmdline.