Keep in mind that the kernel sources are dropped early after a device release. As such, they're generally slightly outdated. This is problematic on a number of devices (generally, the first two devices in a Mark), with the top contenders for shit going awry (panic, deadlocks) held by the Aura and the Forma.
So, while this is fun for tinkering, I'd keep to custom *modules* on production devices.
Or you can try to beg Kobo for up-to-date source drops
.