Sorry to bump the oldness, but what exactly did you do to get the kernel to stick? I've uninstalled SS since upgrading to PB1 and I also have an unlocked BL with TWRP. Every time I flash the kernel in TWRP, it doesn't stick.That was because custom kernels were not allowed go be installed with locked bootloaders. Now you can do it with the unlocked bootloader and TWRP.
Last, anyone has any idea why my Kernel installation doesn't stick after rebooting? It is like the stock TW 5.0 reinstalls the old kernel when I reboot lol
P.S. fixed, it was because SafeStrap unninstallation did not succeed.