The kernel is a detail of all of the devices supported by the OS?. The smaller the kernel, the more lean the OS is. Although the smaller the kernel, the fewer components that would work with the OS. With this in mind, the OS will have a native kernel which is what is installed in the computers produced by Senitrus. For example, since only Qualcomm CPUs are used, this will mean the native kernel does not have to support MediaTek CPUs or x86 CPUs. This improves stability, and make the system perform better.
There will be an expanded kernel which will exist only because there is a subscription model of the OS that is designed to meet with the options of many systems such as x86 CPUs. The kernel will be more bloated, and therefore can cause some issues with devices that may have some obscure or too new of a product in their machine. Building a kernel I would imagine is not easy work. With that said, too new of devices may not work properly. However, Senitrus will try to support system components as they come out. There will be a team dedicated to the subscription model of the OS.