In `kernel/sony/msm-4.14/common-kernel` you'll need to run the `build-kernels-gcc.sh` I'd recommend removing the other platforms or you'll be waiting a few hours on them all building. It's also recommended to use the Linaro GCC Toolchain for this.
Hope this helps.
Ah sorry guys, I'll add that to the OP.
Personally I've been running this for a few months as daily and I'm pretty happy with it. We just never got round to building for suzu as I'd put in a stupid flag that was causing a 4-5 minute boot time. ?*♂️