I just wanted to post the list of working custom Kernels and Kernel tweaks I've testing and have worked 100% after rooting with this method. I'm currently using the TMobile LG Aristo 2+ LM-X212 with Tecknights Oreo 8.1 ROM.
More stars=better
Ferodroid Engine 1.1*** | TWRP Flash | Currently Using with Great Results
LKT 1.5.0** | Magisk or TWRP Flash |
NFS-Injector 4.5 GodSpeed & 4.0 Firestorm** | Magisk or TWRP Flash |
CVC Kernel* | Magisk Flash |
Advanced Charging Controller* | Magisk Flash |
TWEAKS
Ram Tweaks by Crok*** | Magisk |
Low-Ram Config+ *** | Magisk |
CPU Turbo Boost*** | Magisk |
Currently testing CrossBreeder but I DO NOT RECCOMMEND it because its breaking root unless your rooted with SuperSU Binary. I'm fairly certain all these can be flashed with TWRP but I'm only posting as such on the stuff its documented to be OK to do with AND I've tested personally.
I wanted to add that I just recently injected Spectrum compatibility into Ferodroid Engine, and have customized the 4 Profiles successfully.